Agreed on Executioner. Currently useless. Might become useful if we get monsters with large amounts of health, rather than armour, and if the ‘below 50%’ part is removed. Right now it’s utterly inferior to Sundering Strikes.
Killing Frenzy would have been insane if it stacked, but it’s fine in its current state.
Push the Advantage doesn’t seem that OP to me, because you do need to set it up and then still have enough fatigue to utilise it.
Fast Adaption is powerful, but not too powerful. I’m fine with keeping it at 15%.
I think the power of Debilitate is acceptable, since you need to build up the user and set the attack up for it to become effective. As you say, nerfing would also run the risk of making it inferior to a passive perk. Maybe you could lower the percentage, but have it last several turns? That would stress the importance of multiple characters being able to benefit from it.
