Streamlining Warrior Stances

[Reynhart]

Drop Fell Cleave to level 35 with a potency of 300, make it turn into Inner Beast when under Defiance, and make a trait at level 54 to give it an extra 200 potency.

Personally, I think Fell Cleave could stay as it is, because as you said, 35-54 is now old content. What I would do, however, is remove Inner Beast and just make Fell Cleave absorbs HP and reduce damage taken when used under Defiance, but still be affected by the damage penalty.