The Dual-Face Io - Dual Boot and Mobile Fountain

The thing is, Arcane Boots and Mekansm completely outdo the Urn of Shadows + Soul Ring + Bottle combo because again, the latter combo is single target. The former regens everyone. That justifies the extra costs involved, esp because when you jump in a team battle (either through Tether or Relocate), you help everyone and not just your teammate. The Tranquil Boots is for lane staying power, which is absolutely what you're supposed to do.
Secondly, Bottle is for mid laners, and rune users. Worst of all, it can be denied, makes it useless when the fight is on. Same goes for Urn of Shadows as hero or tower damage (the time you'll be most needed), both cancel that regen too.
Also, Soul Ring just reduces your HP, something that the enemies are good at, too.

And finally, everyone needs atleast one set of boots.

I ve consider double boots some time ago .I think its decent but arcane boots is too much for wisp.
You can have pretty much the same result with a bottle urn and soul ring.
Let me do the math for you 1450+975=2425
Urn+Soul Ring+Bottle =875+800+600=2275 and some more stats (though no boots)

Jungling on Io would require you to build for the jungle, unless you level and use the (expensive) Spirits, which reduces mana for ganks/counterganks, especially in the faster games. Getting Last Hits on out of range creep in the lane with a melee hero is fine, and I thought people would consider it common sense.

Tranquil Boots are bad for jungling, though it still might be possible with Power Treads. The only feasible jungle build I can truly see is one with Arcane Boots, though. Will add that to the section.

Getting last hits/Jungling on Io is not wrong.

It is the primary way for him to sustain levels and farm in a dual mid situation with a Chaos Knight (most likely, but not necessarily). As a support, Io should be the one who pulls/stacks while occasionally damaging and eventually getting the nearby camps using his Spirits. Though of course taking last hits from your carry that he CAN take is wrong, that does not mean that Io should be a completely starved hard support, especially for a hero that depends so much on getting level 6.

Overcharge is picked at level 3 so that you can reduce your HP to Tether regen, because quite a few items don't go across tether unless they're working on you.

Thanks for the item help, but I put Orchid Malevolence in there at the very last, as if you have left over gold and Bloodstone, extra silences always help. I have made it clearer that those items are NOT core build, just in case. As before, they aren't present in the Purchase Order section. Anyway, extra disable is amazingly useful, esp considering how fast you can tether and get close to use your items. Also, these give stats, which transforms into regen across tether.

Thanks for the bracket tip, btw.

Note: Am working on getting video clips for the skills, showing how they'll be used. Still working on team section (to include - Positioning, Timing and Juking).

P.s. I never mentioned Phase Boots - the First Phase referred to the First Phase of the game. - Corrected that to "Early Game" to avoid confusion.

Meh, this guide is pretty vanilla, could help a newbie to get into wisp but its not going to tell anything new to a experienced player. In case of Io you should include more information about communication with the team and positioning, maybe some videos, also try to [bracket] any item, spell, hero, so it links and its easier to spot. Some pictures for the spells also help to keep order. I strongly dissagre at the [Orchid Malevolence] pick up because you are the hard support, thats a ridiculous amount of money for a 5 sec silence and your objective is not to deal damage, also you should include in what situations you should pick up some of the items you include in the build, like [Scythe of Vyse], no one should pick this up if you have a disabler on your team, such as [Bane] or [Lion], and what other options are viable. I do like the [Bloodstone] pickup though, as low hp [Io] has having a deny its a handy option and the regen its nice with the stacks you get from winning teamfights and [Relocate] ganking. The quick respawn can also help a lot your team too.

What is picking up [Overcharge] in level 3, its not viable at all, since you dont have the hp pool nor the hp regen to keep it going, I suggest you delay it until you get a [Bloodstone] in hand or getting to level 10, whichever happens first, that way you will have the stats to use it properly.

Getting [Phase Boots] its the worst thing you can do for various reasons. 1) You dont need extra MS because [Tether] lets you slide through terrain and escape easily, even with friendly creeps. 2) You dont need extra damage at all, you are the hard support, stay safe at the back and heal. 3) Getting some support oriented boots will help way more to win your lane, or recover it if necessary, for instance, if your lane partner is [Tiny] or any mana hungry hero, get [Arcane Boots] or course, and if you are getting harrassed or need extra hp regen, pick up [Tranquility Boots]. Even getting some Power Threads will help more since they provide you with solid stats early game.