High-level mid Invoker guide

Introduction

My name is phsc, I'm not really a pro player, but I'm a 5,5k player, I play mid/carry, and Invoker is my favorite and best hero.
INVOKER IS A REALLY HARD HERO TO PLAY WELL, DON'T FIRSTPICK HIM THINKING YOU'RE GOING TO SNOWBALL, MAYBE IT CAN WORK IF YOU'RE LOWER THAN 2K MMR BUT DON'T DO IT, PLEASE
If you want to learn Invoker, it's not like playing any hero, it takes time, and I would say it's a good idea to get on a older account/create a smurf to start playing him, or just play pubs, no ranked until your 20-30th game, if you want to win.

A FEW SKILLS IN THE SKILL-BUILD ARE BUGGED, IT'S:
E-W-E-Q-E-Q-E-Q-E-TALENT-E-W-E-W-TALENT-W-W-W-W-TALENT-Q-Q-Q-Q-TALENT
1-2-3-4-5-6-7-8-9-10-1-2-3-4-15-6-7-8-9-20-1-2-3-4-25

also, this is just for curiosity, this is the highest damage I could get out of Invoker without right-clicks, don't try it in a real game tho... please, just use Cataclysm with Refresher Orb or shard when the entire enemy team is disabled and it's doing 2500/5000/7500 damage if all of them hit, not really a common thing tho... Play Video

Skills

I could do some beauty thing with skills and numbers, but I'm not going to because it's useless.

Exort: Your bread and butter, level up it first, EEE, R, D in the enemy base, casual Sun Strike to see the enemy items, who's going mid, wards, smokes, etc.
Wex: Not really useful early-on, use it at level two, EWW, R, casual alt-Ds, Alacrity is really good when under tower fire or hitting enemy heroes affected by Cold Snap, later on you can use it for bonus movement speed while running around the map.
Quas: Really good early on, with level two, it's really good versus lane-harass, depending on the enemy midlaner, just level up it at level two, if you want to.
Invoke: You don't need to level up it right now, so... press it to invoke stuff, it has a 6 second cooldown, with scepter 2 and with Octarine Core 1.5, and yeah, it matters...

INVOKER SKILLS:

Sun Strike: EEE - Your best damage skill early-on, keep a look around the game to throw it, not really useful for combos and stuff, but really good for getting people that are escaping, it is a global skill, you don't need to leave mid to gank,
just throw it, and gg ez kill ez mid ez farm, also, early on, use Alacrity or Sunstrike or Cold Snap early on, summoned, because they're the best skills you got, if you want to use it later on, Tornado or side Ice Wall or use it on a person affected by Cold Snap, and you can also use Eul's Scepter of Divinity and Scythe of Vyse, and also remember to put it a bit on the back of a person if you're going to use it with Deafening Blast, and remember, it pierces Black King Bar.

Alacrity: EWW - Really good at farming and harassing, but really useful for farming, go into the jungle, use Hand of Midas at the big creep, and farm really fast, go back to the lane, farm again, stuff like that, you can also use it on your Forge Spirit or the catapult creep, good at your carrys or when you have Scythe of Vyse or Bloodthorn.

Cold Snap: QQQ - Really useful early-on, you can use it for a lot of stuff, canceling Salves or Bottle charges, killing people that are diving or escaping, getting an easy Sun Strike, really good with Forge Spirit and Alacrity, useful with Urn of Shadows if you know what you're doing.

Chaos Meteor: EEW - Useful for a lot of stuff, farming, triggering Cold Snap, and doing damage, a lot of damage... probably the skill that does most of the damage in a teamfight, if you want to use it, Tornado before, or Cold Snap, or use a side Ice Wall, maybe Eul's Scepter of Divinity, maybe Scythe of Vyse or Bloodthorn.

Forge Spirit: EEQ - Really good skill, you can use it for farming and damage, but more for split-pushing for your much-needed farm, start using it at around level 15 where you're going to have your Aghanim's Scepter, combos well with Ice Wall, Alacrity and Cold Snap.

Deafening Blast: EWQ - One of the most useful skills you got, it disarms, and does damage, but doesn't go through Black King Bar, but if someone activates it after you've used it, that person is still disarmed, really useful in teamfights or solo kills.

Tornado: WWQ - Probably Invoker's best skill, useful for farming, fighting, saving, disabling, initiating, useful with basically every skill the hero has, just throw it, and don't **** it up.

EMP: WWW - Really good but kinda hard to use, and it doesn't have a lot of damage, but burns the mana, useful in teamfights to recover your mana after a combo, most of the times you're going to use it with Eul's Scepter of Divinity or Tornado, but remember, it has a 2.9 second delay, so... depending on your Tornado level, throw it before the Tornado, same for Eul's Scepter of Divinity

Ghost Walk: QQW - Always remember this, going to die mid, or in a teamfight? just use it, can also be used for initiations but not recommended, if possible, QQQ before using it or WWW, as the regen/speed might save you, really good escape ability, you can combo it with Ice Wall or Forge sprit

Talents

LEVEL 10 - Why wouldn't you take it? pretty simple, it sucks! you're not going to kill people at lvl 10, you're going to farm, maybe get a kill with Sun Strike, the only reason I see this coming is either for farming stacks, but really big ones, teamfight combos with a Magnus or an Enigma that got an early Blink Dagger or if you went for an early Eul's Scepter of Divinity

LEVEL 15 - Basically always the +1 Forge Spirit, it's the biggest talent winrate difference in the game I think

LEVEL 20 - This one depends, is there a wombo combo ally in your team? Faceless Void, Enigma, Magnus, Tidehunter? if there's one pick it, now, can you do the badass Deafening Blast lvl 25 Refresher's Orb combo? if you can, pick it, if you can't, get the Alacrity buff
2018 JULY UPDATE: After lots of playing, Cataclysm is better, just a 2500 dmg global presence skill, 5000 with Refresher's Orb

LEVEL 25 - The hardest decision, both are really great, really great, Deafening Blast as a area effect is really good versus right-clicking cores, and in teamfights in general as it increases your damage a lot, but the cooldown removing ability of Tornado is really broken and you can just spam it, killing creep waves and doing a lot of damage, if you're balling, with Octarine Core, go for Tornado, if not, Deafening Blast.

Items

STARTING ITEMS
Shared tango - You need the branches, as they give a lot of stats and you need them you can also go for Faerie Fire + Iron Branch, but I prefer the three Iron Branch build as you can use two for Magic Wand.
Iron Branch - Really good with the Shared tangos, as you can use them on a Iron Branch and get two times the regen, BUT A WHILE AGO IT WAS KILLED, so now you get two branches and be happy with your two tangos

EARLY GAME
Salve - One Salve early on is probably going to be good, as Invoker is probably going to get out of the lane versus heroes like Tinker and Sniper.
Hand of Midas - Really good for Invoker, a hero that likes both the gold and the XP, get it, I get it around 6-9 minutes, with/without the Salve winning or losing mid, depending on how it's going, go for Boots of Speed or Magic Wand first.
Boots of Speed - You don't need Phase Boots or any other choice as Invoker, as Wex gives speed, and you need your Hand of Midas.
Magic Wand - Invoker is the king of escapes, this item is amazing on basically every hero, get it, nice stats, nice escapes and good plays.
Null Talisman - Good if you're lacking damage/HP/mana early on, I like to get it versus heroes that have decent damage or when I'm fighting a lot early.


CORE ITEMS
Aghanim's Scepter - This is the item you need to fight, without it you're a Sun Strike throwing right-clicker with a stun called Cold Snap, you really need it for fighting, I get it around 15-20 minutes, depending if I'm winning or losing, go for it, then fight.
Boots of Travel - Invoker is a good split-pusher, use it with Forge Spirit, get a tower, Alacrity it, teleport into the fight that is going on, kill everybody, get another tower, gg wp.
Blink Dagger - This is a item that I haven't been going for lately, as when you're a better player, you don't need to blink in to initiate, as you really know timings and skillshoting the initiation with Tornado, get it, escaping and initiating is the thing.

IMPORTANT ITEMS
Shiva's Guard - Do they have physical damage? get it, they don't? still a good choice as it gives a lot of mana and slows a lot.
Octarine Core - Really good teamfighting high-ground defense item, get it, almost always it's a good item, nice values of HP and mana, the cooldown reduction is kinda broken and... spell lifesteal will save you a lot and will make you kinda tanky.
Refresher Orb - Do you know what you're doing? Probably not as you're looking at this guide, practice a lot with this item then get it, I'll talk about combos later, but really good late-game item, just don't do **** with it.

LATE-GAME ITEMS
Scythe of Vyse - Sheepstick is godlike versus heroes with escapes like Slark or your biggest enemy, Anti-Mage, really good for combos versus heroes that can disable you.
Bloodthorn - Really good item, but really hard to use well with Invoker as it is really costly, good late-game, probably my last item in games I don't go for any situational item.
Also consider stealing a REFRESHER SHARD from your team, as you can do some crazy stuff like in the beginning!

SITUATIONAL ITEMS
Drum of Endurance - Are you watching this in 2013 even tho I made this in 2017? get it.
Eul's Scepter of Divinity - Do they have silences? do you suck and you can't do hard combos? get it, also the mana regen is nice.
Rod of Atos - Is there a Storm Spirit or a Puck? really good versus them, no mana regen, and kinda bad stats and you don't get regen off it.
Linken's Sphere - Do they have silences? are they AOE? Orchid Malevolence? get it, really good with stats, I like to get it kinda early for the mana regen and surviving ability.
Aegis of the Immortal - Invoker is a good aegis hero, as he can just Tornado, TP and Ghostwalk out, Cheese is also good.
Black King Bar - Are you higher than 2k? then you probably understand why you're getting this... magic immunity is broken.
Hurricane Pike and Force Staff - Really good items, not really common, good for escaping and kiting, don't build it if you don't know what you're doing, pros like it.

Pros / Cons

PROS:
-Really high damage and versatile hero
-Really good for your team
-Hard to counter-pick if played well
-Really high skill-cap
-The god of mid-late game

CONS:
-Hard to play
-Hard to play in a good level
-Really bad if pressioned early-on
-Needs a lot of farm... and mid, only mid

HOW TO COUNTER INVOKER:

A few heroes destroy Invoker mid, I'm only considering the Exort meta one
Tinker(later on he's easy to deal with as Tornado gives vision and he's pretty squishy, you can use Cold Snap to counter his Rearm and EMP too, Sniper (just squishy, a long range combo like Tornado into Sun Strike into Deafening Blast can kill him but its pretty hard to pull of), Storm Spirit(again, EMP and Cold Snap kill him, but he's going items that counter you, Templar Assassin.
A lot of hard-carrys destroy Invoker
Anti-Mage( Cold Snap counters him tho, Juggernaut, Lifestealer ( Sun Strike piereces spell immunity tho)
And tanky heroes Invoker can't kill, or heroes that counter-initiate or have silences
Centaur Warrunner , Tidehunter, Enigma, Magnus, Puck, Death Prophet, Rubick.

Combos

Items with * around them are optional
EARLY GAME COMBOS:
* Forge Spirit* and * Alacrity* into * Ice Wall* into * Cold Snap* into Sun Strike
Tornado into * Cold Snap* into * Ice Wall* into EMP
Most of the time you're going to improvise early on with what I used before, don't use Deafening Blast as it costs a lot of mana, and don't try to use Chaos Meteor early on as it probably isn't a good idea, same for Tornado if going for an Exort build as this guide says to

MID GAME COMBOS:
Eul's Scepter of Divinity or Tornado into Sun Strike into * EMP* into Chaos Meteor into Deafening Blast into a right-click combo listed before
Deafening Blast into Cold Snap into Chaos Meteor
At this point don't try to go for really hard-combos, Eul's Scepter of Divinity or Tornado for initiation, most of the time Chaos Meteor or Deafening Blast are going to be the AOE damage and right-clicks and Sun Strike the single-target burst.

LATE GAME COMBOS:
Eul's Scepter of Divinity or Tornado into Sun Strike into * EMP* into Chaos Meteor into Deafening Blast then Refresher Orb then Deafening Blast into Chaos Meteor into * EMP* is the way to go, you can go for a Sun Strike or Tornado into Sun Strike at the end but I prefer throwing an side Ice Wall and right-clicking with Alacrity
Also, use all your disables like Bloodthorn or Scythe of Vyse into the enemies if you're doing this.
And the Refresher Orb combos are really hard, practice them before versus bots or in the practice thing.

MY FAVORITE COMBO EVER IS:
Tornado into Sun Strike into Deafening Blast
it's hard to pull off, does around 1300 damage, I like to use it on supports during mid-early game, some times it wont kill but it can be enought to get someone who's escaping, keep in ming that with level 3 Quas and Aghanim's Scepter the Tornado lift time is 1.5 seconds, and that is the Sun Strike delay, so just Tornado and as soon as the target gets hit use Sun Strike, do this as soon as you get your Aghanim's Scepter

Midlane

So... you're playing Invoker in the midlane, as you should, mid lineups might be kinda hard for you, so I'm going to talk about every mid hero you might get and a few roamings.
I'm going to use a difficulty level-thing
1: Easy
2: Medium
3: Hard

Alchemist : Not really a problem, you're probably going to have more damage, Quas really ****s up with Acid Spray and you can harass him and deny a lot. Difficulty: 1
Arc Warden : Might be kinda hard early on, later on you're going to outdamage him, it's kinda hard to deny a good arc warden as he's going to use Spark Wraith to secure the ranged creep, and at level 6 he's probably going to kill you, just play safe and keep farming. Difficulty: 2
Bounty Hunter : If he's roaming, it's a pain in the ***, a big slow, no Ghostwalk if he has Dust of Appearance, probably you lost mid if you don't get help. Difficulty: 3
Clinkz : He has more damage than you, so you're not going to deny, killing him isn't easy, still, he's really bad at denying, and Clinkz is really squishy, so you can kill him. Difficulty: 2
Death Prophet : She has bad damage, so you can outfarm her, still, Crypt Swarm might be a problem to deny the ranged creep, anyway, she's not that tanky early on so you can get a few kills, but Exorcism might give her a kill and get your middle tower. Difficulty: 2
Dragon Knight : You're not killing him after he gets two points into Dragon Blood, still, you do some decent damage, and with help you can kill him, but you can lose your middle tower and Breathe Fire reduces your damage so it might be hard to farm or deny. Difficulty: 2
Earth Spirit : He has a silence and a stun, and a way to initiate on you, you probably lost mid if he's roaming and nobody is helping you, just play safe, try to farm the jungle and get the XP from the lane. Difficulty: 3
Ember Spirit : He's not a big problem, Tornado dispells Flame Guard, you got more damage, still, he might get a kill or two, and you can get two or three, you can also outfarm him really well. Difficulty: 1
Huskar : You got more attack range, damage, and pure damage with Sun Strike, just harass, farm, get a kill, and Quas can really help you in lane. Difficulty: 1
Keeper of the Light : He's a pain in the ***, you know mana? no, you don't, also, Mana Leak allows for an easy initiation and no Ghostwalk. Difficulty: 3
Kunkka : Tidebringer might be a pain in the ***, and also the X Marks the Spot into Torrent into Ghostship is an easy kill on you, but you got more damage than him, but he's tanky. Difficulty: 2
Leshrac : More damage, more attack range, and he's really squishy, harass him, Alacrity + Cold Snap into Sun Strike, easy kill, just keep in mind you can't leave the lane as he's going to destroy your tower with Diabolic Edict. Difficulty: 1
Lina : She's a big problem, she has magic damage that will harass you a lot and also get the ranged creep most of the time, she has more attack range, still, she has less attack damage and a bad attack animation, also she has a stun and Laguna Blade is a big problem, she just destroys Invoker in lane most of the time, also, if you leave lane, say bye-bye to your middle tower. Difficulty: 3
Lone Druid : This guy might be a problem, that bear of hell harassing you while he farms, also he has a permanent double-damage rune, and he can just dive you into death, Ghost Walk is your friend, just keep it in mind, you can also get a kill on him if you got someone roaming around, and your middle tower might be dead when you go to the jungle after dying two times to that hero of hell. Difficulty: 3
Magnus : I consider Magnus and easy mid versus Invoker, you got more damage, you can harass him, also, Cold Snap can stop Skewer some times, and you can secure kills with a nice Sun Strike, not a big problem. Difficulty: 1
Medusa : She's going to spam that ****ing snake and remove your mana, so no Sun Strike or Ghostwalk, but you got more damage so it's ok, just farm, that's it.
Difficulty: 2
Meepo : He's a pain in the ***, if he gets a good net on your you're dead, if you leave mid your middle tower is dead, still, keep in mind that versus Meepo a casual Chaos Meteor might be good, maybe even Tornado, just don't feed him, and harass him a lot in early levels, and keep in mind, later on, you can counter him. Difficulty: 2
Mirana : Sacred Arrow, that's it, and Leap, if you're really good with Sun Strike you can kill her, if not, just don't get arrowed in the knee, also, if she's roaming, you're ****ed up.
Necrophos : Accept it, you lost mid, you're not killing him unless he's really bad and he might just get a few easy kills on you with Reaper's Scythe, but if you're a good Invoker you can just play safe and outfarm with your higher damage. Difficulty: 2
Ogre Magi : Going to gank mid, has a stun and a slow, probably going to bring Dust of Appearance and he's going to dive in, accept it, and move on, you lost mid if you got no help. Difficulty: 3
Outworld devourer : Don't let him use Astral Imprisonment on your and also don't let him build inteligence with Arcane Orb, you can get a few kills and Astral Imprisonment allows for some easy Sun strikes, and remember, you got more damage and more inteligence than him. Difficulty: 1
Phantom Assassin : She spams that damn Stiffling dagger, if she has Blight Stone, you're probably going to have 0 armor or -1, just harass her and get some easy denys and farm, with Quas helping you, maybe a kill or two with some help or when she dives you. Difficulty: 3
Puck : Early on, more damage than you, also has two escapes and a silence, at level 6 can get an easy kill on you with Dream Coil, just keep farming safe and denying if you can. Difficulty: 3
Pudge : Pretty simple, got hooked? you're dead, got hooked again? you're dead, don't get hooked, and you're going to need wards, good thing is that if he's roaming he's going to remove them, so you can see you lost. Difficulty: 3
Queen of Pain : Spams of hell, still, Blink and Cold Snap aren't friends, and she's squishy, you might get a few kills, just keep in mind that she can kill you,a nd survive the spam of hell, and try to farm but she has high damage and a good attack animation and projectile. Difficulty: 2
Razor : He's not that much of a problem, just don't let him build damage, not really tanky as you think, and you got a lot of damage, he doesn't, just farm, don't lose the middle tower, and don't use Cold Snap on him because Unstable corrent.
Difficulty: 1
Riki : Smoke Screen and invisibility, you're ****ed up if nobody gets some Sentry wards, keep in mind he's going to **** you up until the end of the game, just farm, try to outfarm him and the enemy midlaner, and get some easy kills on him after he finishes with his ult by throwing a Sun Strike. Difficulty: 3
Rubick : Most of the times he tries to gank me I end up killing him, just hit him, he's weak, the only thing he has is Telekinesis and you know... Sun Strike to secure the kill then QQQ and run to the shrine, but if the enemy midlaner is a Lina you're dead. Difficulty: 2
Shadow Demon : The same as above, hit him, if he uses Disruption on you, just QQQ or WWW and run, if he uses it on him, Ice Wall and hit him, just keep in mind there's an enemy midlaner. Difficulty: 2
Shadow Fiend : Not that big of a deal, don't let him build damage, deny a lot, farm a lot, harass a lot, if he goes on you, Cold Snap, and don't get razed. Difficulty: 1
Silencer : He has silences, harasses a lot, and a lot of damage, try to farm, maybe get a kill in other lanes with Sun Strike and farm the jungle a bit, later on get an Eul's Scepter of Divinity to dispell the silences. Difficulty: 3
Skywrath Mage : He's really, really squishy, outfarm him, harass him, kill him, and you know, Quas is your friend, but remember, he has a ton of damage and a silence. Difficulty: 2
Sniper : Shrapnel sucks, he has more damage than you, and a giant attack range with a really good attack animation, still, no damage, outfarm him, don't lose the middle tower, and keep outfarming him, maybe getting a kill or two. and Quas helps a lot versus him. Difficulty: 3
Spirit Breaker : If he's going mid, you're probably dead, play safe, farm, then go back into the game when you're stronger. Difficulty: 3
Storm Spirit : He has more damage than you early on, he's kinda tanky with his high armor, and get can kill you, also he builds Orchid Malevolence so go for Eul's Scepter of Divinity as Linken's Sphere can be triggered by other stuff he has, just play safe and farm, don't get killed, and if you want to win mid just go Quas Wex Difficulty: 3 or Difficulty: 1 if Quas Wex
Templar Assassin : She has a lot of damage, she reduces armor, and she's really hard to kill, not killing her without help, and don't die, also she has high attack damage so try to farm and deny but that's not easy, don't lose the middle tower and it's ok, keep in mind she farms faster than you. Difficulty: 3
Tinker : Laser blinds, so you're not farming well, he can get easy kills on you, and your middle tower, play safe, don't get killed and don't lose your middle tower, really hard lineup as Tinker farms faster than you, and you can also go Quas Wex and destroy him. Difficulty: 3 or Difficulty: 1 if Quas Wex
Tiny : Harass him, he has a lot of damage, so secure your ranged creep, and don't let him pull the aggro of the creeps, and keep an eye into runes, and don't lose the middle tower, neither die. Difficulty: 2
Troll Warlord : Harass him, he has a kinda high base damage, armor and he has evasion, so keep that in mind, play safe, outfarm him, don't lose the middle tower, don't die, yeah... Difficulty: 2
Tusk : Snowball is an easy kill, just go under the tower and try to kill him and not die, still, might be a problem. Difficulty: 3
Viper : You're not killing him, never, don't even try to harass him as you're going to get damaged, maybe later on with two points on Quas, play safe and outfarm him, denying a Viper is really hard, and don't leave the lane as he destroys buildings really easy, and he has magic resistance so, no Chaos Meteor. Difficulty: 3
Windranger : She's squishy, just harass her a bit, when she goes for Powershot Sun Strike into Cold Snap into attacks, you might get a kill if the player isn't skilled, if he is, just harass, then later on throw Sun Strike, but you got more damage than her so it's ok, and don't leave mid as she melts towers. Difficulty: 2
Zeus : Quas is your friend, play safe, try to farm, farming under tower is the thing, you can also try to kill him as you got a lot of damage, just keep in mind he also has a lot of damage, and Quas is the thing versus the harass he does. Difficulty: 3

Early-game - Mid-game

In this part, I'll teach you what to do when you win mid, lose mid, or go even with the enemy midlaner.

DID YOU WIN MID?

If you won mid, this means you got your Hand of Midas by 4-8 minutes, you should go to Aghanim's Scepter and keep farming until you get it, also try to get the mid tower, try to be active with Sun Strike and maybe get a few kills, but don't think you're a god and you can kill everybody, with Aghanim's Scepter you are, without it you're basically a right-clicker with a few skills, you should get your Aghanim's Scepter around 12-18 minutes and then, go fight and push.

DID YOU LOSE MID?

If you lost mid, you need to recover your farm, look around the map for Sun Strike kills, a thing I do most of the time I lost and maybe even if I won mid is that I throw a Chaos Meteor in the midlane, farm the wave and push it near the tower, then go into the jungle to use my Hand of Midas in the big creep in the big camp, farm the camp, then farm the medium camp, go back to mid, farm mid, farm the jungle... etc, keep doing it until you're strong, if you lost mid, you should get your Hand of Midas almost always, as you need the gold and XP, talk to your team if you really lost mid about buying a Tome of Knowledge to try to get back into the game, after your Aghanim's Scepter go fight, try to make a comeback with the power-spike of it, if you can't(if the enemy team has a realy big teamfight power, with someone like and Enigma or Earthshaker, try to split push and keep farming.

DID YOU GO EVEN MID?

If this happened, do the same as you do when you're winning, but throw the Chaos Meteor in the midlane, don't go for towers that early, and fight with Aghanim's Scepter.

Mid-game - Late-game

Mid-game with Invoker is probably the hardest part, you should build items to counter the enemy team, and get towers while also winning fights, first of all, keep using Forge Spirit to split push, if possible, use Boots of Travel to get a few towers, but remember, don't die, Invoker is a hero which you can't die, maybe one or two times at max, keep farming but fighting, you don't need 15 cs/min with Invoker, 7 or 8 cs/min is good enough if you're winning fights, you can try to get a few ganks, and you really should if you made a item like Eul's Scepter of Divinity, and depending on your carry, you should open space for him(if someone like Anti-Mage or Morphling), or you should go get towers with him(if someone like Drow Ranger or Phantom Assassin, maybe even Terrorblade), and remember, use Alacrity on them, not you, they do more damage, keep that in mind.

Talking about items now, do they have some armor-reduction or really hard hitter hero? ( Phantom Assassin, Terrorblade, Anti-Mage, Shadow Fiend and even Slardar or Elder Titan), go for Shiva's Guard fast, as you're going to need it, it is also really useful to kite people.
Do they have a hero with a really strong targered skill? ( Legion Commander, Bloodseeker, Terrorblade), go for Linken's Sphere which is a really good item to go early, some times I even go for it before Boots of Travel because it gives really nice stats and a nice HP and mana regen, you can also go for Orchid Malevolence if you're fighting a lot, also go for it when you're agains enemies with escapes which you can't do **** agains't( Slark, Anti-Mage, Juggernaut)

AND REMEMBER, IF YOU GO LATE-GAME WITH INVOKER, IT'S NOT AN EASY WIN, PROBABLY THEY'RE GOING TO HAVE A Black King Bar ON THEIR CORES, SO IT'S NOT JUST GOING IN AND DOING SOME SICK Refresher Orb COMBO, YOU NEED TO PLAY REALLY WELL TO WIN.
Late-game with Invoker is really simple, go in, explode everybody in a sick teamfigh with Octarine Core and Refresher Orb, if there's someone like Magnus or Enigma, if not, bait their Black King Bar's, also, you should get one depending on the game, then, kill the enemy cores, push one or two towers, and play safe, don't be greedy, this already ****ed me up so much, i'm talking about more than 100 games lost because of me being greedy with barracks or towers
If it really goes late-game, you're going to get Moon Shards to your carrys first, then you, you hit hard, but they hit harder.
If you're not able to defend high-ground with Invoker for reasons(example: Juggernaut and Blade Fury), it's ok, it's not really your fault as you can't really do ****, Invoker wasn't a good pick, or they just counter-picked you, or maybe you just played bad.

The end

Invoker is a really good hero so... practice a lot
If someone liked this, I may make more guides or make this guide better... so yeah, good luck with your ranked games after becoming a Invoker god.