Magic is an abomination!

Introduction

Greetings! Today is the day when "magic shall not prevail"! And in order to end all sorceries, the best "tool" will be Anti Mage (although he seems to depend on magic himself *looks at "Blink" and "Mana Void"*) Anti Mage is a hard carry, with insane potential if farmed well. The main Pro for Anti Mage is that he can turn the tables of virtually any game. So, let's discuss why is he so unique!

Pros and Cons

Pros:
Counters any hero with magic damage
Fun to play
Great to disable enemies
Can turn the tables of any game
Not very mana dependant

Cons:
Very farm dependant
Squishy early
Useless without sufficient farm
Death is unforgivable!
Can be easily escaped

Early Game

So, your first item should be "Blink". The mechanism is simple, it's a short distance teleport, which allows you to initiate, or escape. As I said before, Anti Mage is very squishy early, so you need to ensure that escape for good. Your first items should be Tango and Poor Man's Shield. Anti Mage has the potential of insane agility gain, so you need to focus on that. Pay very close attention to last hits. You HAVE TO farm, with enough farm you can become unstopable. Without it, you're absolutely useless. Try to avoid attacking your enemy and be very careful. Every second lost means you're losing precious seconds of farming.
Your next items should be Quelling Blade and Ring of Basilius. Good for farming way more efficiently. Next up, upgrade Spell Shield. However, this might be optional. If you're laning with a guy/gal without any magic damage, you better get Mana Burn. Then, the other option. So, you're level 3 and have 3 skills at level 1. What's next? Stats! Nothing helps you ensure your endurance more than stats. Keep them upgraded until level 6 (obviously). A quick discussion about Anti Mage's ulti, it deals damage based on the missing mana and that damage is dealt to nearby enemies too. It's a ranged attack and should be good to finish off your enemies. However, if your enemy has full mana (or very small amount of mana missing), that skill ain't gonna do a thing. So, time it carefully!
Back to the items, your next item is going to be Power Treads. You're gonna keep it on Agility for good. It's a useful thing, because you increase your Agility, thus your attack speed (which is essential). Anti Mage doesn't require bonus damage and increased movement speed for a small duration (Phase Boots), he doesn't require quick HP regen (Tranquil Boots) and he DEFINITELY doesn't require mana regeneration (Arcane Boots). So, yeah, Power Treads is the obvious choice.
Level 7 is another upgrade for stats and level 8 is upgrade for Blink and you're gonna make sure that Blink is maxed, which will be done at level 10. Level 11 is another upgrade for Mana Void.

Mid Game

After Power Treads, get a Perservance. It's an important item, because it builds into BATTLE FURY! Ah...Battle Fury! Immense power for Anti Mage! Imagine Mana Burn, cleaved to all nearby enemies and combined with Mana Void! Multiple kills? Possible! So, as soon as you get Perservance, go to the jungle and DO NOT LEAVE. Farm, farm and FARM! Do not engage in team fights unless they are very nearby! If you see a potential for free farm on a lane, USE IT! Just farm and get a Battle Fury! With good farm, you should have Battle Fury by 15 mintues or so. If you manage to get Battle Fury under 20 minutes, it will be effective. After that, seems you are far to late. You can pretty much say after that, you screwed up *pat on the back* So, you finally bought Battle Fury and farming is a piece of cake. I suggest you to not engage yet, because you are not ready with Battle Fury and boots alone. So, my next suggestion is either Yasha or Vladmir. Yes, a lot of people hate me for byuing Vladmir, plus you can't stack Morbid Mask with Anti Mage because of his Mana Break. However, it's a good choice. If you feel like people are squishing you and you have to return to the base a lot of times, my obvious suggestion is Vladmir's Offering, because your lifesteal combined with Battle Fury should be enough to regenerate you some HP for good, so that you don't stop farming. If everything's fine, get a Yasha. Solid bonus of movement speed and agility, which is essential for Anti Mage. Afterwards, get a Vlad. So, back to the skills, now you should max your Mana Break, because you are safely farming wherever you get a chance and you don't need Spell Shield yet. After you max it, it'll be level 16 and another upgrade for Mana Void. Then, max Spell Shield because by then you'll start INITIATING !!!

Late Game / DOMINANCE

This is your moment... You are now preparing to terorize entire enemy team... Are you up for it? Good. You go to the secret shop and buy Ultimate Orb. With just a simple recipe your ultimate weapon is complete. MANTA STYLE! Ready to initiate? You should be. Blink towards the enemy, multiply yourself and right-click them to death. If they escape, blink again. There's just one tiny little thing. People escape you with ease. You don't have anything to keep them in place (except for ulti, but the ministun is too pathetic). They just need to keep a small distance, blink dagger and they are gone to safety. Plus, imagine you are fighting someone with huge health bar (for example Pudge, or Wraith King, or Bristleback, pretty much every durable hero). They'll escape easily, or wreck your face. So, in order to finish of your enemies quickly and remaing safe buy a Butterfly. Great addition to every agility hero. Your attack speed should be terrorising, leaving small chances against your enemies. Plus your evasiveness will represent a terrible pain in the *** to a lot of enemies. But there's another case you need to keep in mind. What if you have some pretty good escapes as enemies? Simple choice, get a Skull Basher. It's good because it has a bash, which makes your enemies really scared of you and it upgrades into a powerful Abyssal Blade. So, yeah, gg ez. Nice victory. With this items in your sleeve, nothing can stop you from winning a good game.

Alternate items

So, there are only 3 alternate items I would like to discuss.

You may actually wanna buy Heart of Tarrasque instead of Butterlfy in one specific case. Your team is filled with losers, you are pushed and the majority of enemy towers are still standing.
If you have some pretty "blurry" enemies *looks at Phantom Assassin* or enemies with Butterfly, instead of Abyssal buy a Monkey King Bar. Same bash, but makes your hits unable to be missed.
If your team needs defending and pushing at the same time, sell your treads and buy Boots of Travel. Easy to move around quickly and win the game.

Friends

Sounds slightly bizzare but Anti Mage's one of the best teammates is actually a mage, Invoker! His Emp drains huge amounts of mana, making your enemies highly vulnerable to your Mana Void.

Another important ally is Lion. If you are supported by Lion, you may earn a decent amount of kills. Combined with Lion's Mana Drain, your Mana Void should be deadly.

A great combo with Anti Mage is Keeper of the Light (shortly, KotL). His Mana Leak drains insane amounts of mana, making your Mana Void very effective.

Another combo is effective late game, because you and him won't be laning together (just like Invoker). However, it requires slight preparation. That is Phantom Lancer. His corest item is Diffusal Blade, with which he drains insane amount of mana because all clones have that ability. So, yeah, another solid combination with your Mana Void.

In overall, pretty much every decent stun and mana drainer is good besides Anti Mage.

Easy Prey

Anti Mage is deadly against the majority of Intelligence heroes. They rely too much on their mana, which makes them easy prey. The weakest hero against Anti Mage is probably Invoker. He uses up massive amounts of mana in very short period of time. Anti Mage is also very powerful against Wraith King, because if he has his mana drained he won't rise from the dead and thus becomes easy to hunt down.

How to Counter Anti Mage

There are some ways to counter Anti Mage, so be very careful. Anti Mage depends on early game and if killed multiple times during early game, he's done. He's very weak against some hardcore harrassers too, such as Huskar (Huskar is also dangerous for Anti Mage because he doesn't rely on his mana pool at all). If Anti Mage is prevented from farming, he's absolutely useless. Early on, he's very weak against Bloodseeker and his Rupture, because if he's forced to stay still, he's done.

Tips

There are a couple of tips I'd like to offer to you.
So, if you are being chased by an enemy and you can't turn around and face him, Blink into the woods. You are harder to be found in there and in case you are found you can deny yourself.
Your Mana Void has a slight mini-stun (which is pathetic, but still is a stun). Use it if your enemy is trying to teleport away from you, in order to break the channel.
If you see a very mana dependant enemy nearby, left-click on them to see their missing mana. You might kill them with your ulti without the actual need of going in melee range and right-clicking them.
Try blinking around the camps while jungling. This way you save a lot of time and become harder to be cought.

Conclusion

So, thank you for reading this loooooooong guide. I hope you found it useful. This isn't the best way to play Anti Mage, it's clearly not the only way to play Anti Mage, it's the way I play Anti Mage and it never screwed with my personal experience. So, good luck and have fun!