I am about to start Act 5.4.4 ...

ThreeFloyd

Here is my roster. If anyone has tips/suggestions, please let me know. I’m thinking Corvus for 5.4.6 Ultron. I have a 4* Medusa that I should have 4/40 by the time I begin the attempt. I know she can shut Ultron down.

ItsDamien

Corvus can work. Just be careful not to trigger power gain or regen while using him though, or you're in for a real bad time. Also choose your path wisely for getting to Ultron. If you're planning on going the rage path, make sure you have a good nullify champ for going that route. I used my 4/40 duped SW and even though each fight took about 100 hits or so, she made fairly easy work of it and didn't have to worry about the stacking rage fury buffs.