Very well. Let the game begin.

This will all be updated once I'm done enjoying Medivh's avian goodness.

Until such a time comes, please remember... No matter how learned and knowledgeable, how wise and how wonderful, how powerful and puissant, there is always one more sliver of power, one more bit of knowledge, one more secret to be learned by any mage. This entire guide is written using the combined experiences & opinions of my coworkers and I. We do not pretend to be experts, or even good players. We have simply found the following spec to work best for us. We would LOVE to hear your constructive criticism on what could be changed, and hope to read YOUR guides when they come out! :-)

(Also, if anybody's a pro at formatting guides -- specifically, how to put various ability icons + hover-tooltips -- please feel free to reach out to me... I'M SO LOST!)

Tier 1
This Tier is going to depend highly on your map / playstyle. Stable Portal is certainly appealing for Infernal Shrines and other "we're going to need to work an objective, off-and-on, for a while" maps, while Portal Mastery will certainly aid you well in maps with a lot of dividing walls where careful placement would be worth-while. Personally, I am a fan of Raven's Intellect, as I found myself bleeding mana like a teenager with a credit card, but that's just my taste!

Tier 2

Tier 3

Tier 4... THE ULTS!
Poly Bomb presents more opportunities for combos, both offensively AND defensively, than Ley Line Seal (the latter having the lovely potential to mess with your teammates' ults, should you not be communicating). While Seal can give your team precious seconds to set up a 4-sided blitzkrieg, or catch-up to members of a mass-retreat, its use has less potential than Poly Bomb, which forces your opponents to sacrifice their formation simply to end the effect.

Tier 5

Tier 6

Tier 7

Remember... it's not all demons and magic in this world. Sometimes a simpler answer suffices.