Hmm. I think that's thematic, but I worry that it would feel like "punishment" to the players. After all, they lose control of their character during the Bout, so to ask them to burn all their Hope points to atone for whatever the LM made them do seems...unfair.In such a highly difficult situation (that probably he has to solve by himself, without help), a real hero should be willing to spend as many Hope points as necessary to succeed. Spending so many Hope points would be similar to having that "super-ability" in effect, but not in cost to the hero, who should sacrifice something for his attonement.
What I was going for is trying to make Bouts less "bad" (from the gamist perspective) by having some bad (permanent Shadow point...or however the new mechanic works) and some "good".