Originally Posted by Shamanic
Why would you get a RoA on Dominion in the first place? In most cases Boots->Catalyst->Deathcap->Lich Bane/Odyn's Veil works way better, especially on Kassadin or other mage assassins.
You get about the same amount of mana and survivability, WAY better utility, and WAY WAY better damage output, not to mention you don't have a set-up time for RoA.
Kassadin is a mage assassin. The only place where you should get RoA is on Summoner's Rift, where the higher amounts of HP are badly needed as well as the catalyst aspect. And even then going for Catalyst->Deathcap is many times the better option.
For Kassadin specifically, you're looking at an approximate 2.0 AP ratio if you hit once with all your abilities in succession, which translates into roughly 2.0x80AP-Charged_RoA=160 damage. Uncharged Odyn's is going to give you a flat 200 AOE
damage, and up to 400 if you've taken heavy magic damage. So certainly it's going to give you more burst and more survivability in a mage button mash race, if you're in melee.
However, if you're working toward a LichBane, RoA is going to fuel that much better.
I find Odyn's to be a fantastic item, but I also see it poorly and prematurely used by tanks who should really let it charge up from some damage soak, and execute as a finisher.