Absurdly good in Jenny Barnes, for who this will (scenario fuckery not withstanding) always be ????, or Unexpected Courage on steroids. Also pretty nice for Rogues with low willpower to pass a "brain test". For Winifred especially this seems like an auto-include if you need a plan to deal with those tests, especially since it feeds her ability. Also combos beautifully with cards that boost all stats, like Geas.

I have a feeling that this might be good in Finn, to get a +3 Willpower, which also could double as a +1 if you really need it. Haven't tried it out though. If you have a way to boost your Willpower or Strength value, it get's even better, but that's probably not that easy in a typical Finn deck.