I feel like this would absolutely need to be just between the player and the dm.. or maybe just the dm plans it and the player is revealed later to be so monumentally stupid that various things just work out because the enemies were drained with nobody really realizing, or the idea was so dumb it worked after some major hyjinks - and the party the whole time would just be randomly failing stuff, but completely unaware of why because they still act like a normal sorc…

The drain would have to come with some sort of “unearned confidence boost” buff that would partially negate the effect for players, though, or it would be really hard to get much done.