I feel Hustle provides a nice risk factor, but I feel at least for me it provides an unfavorable type of risk, something pretty luck based. Something that would be based around making good predictions that can really pay off or really hurt, like Hi Jump Kick, is to my mind the best way to go.
Rivalry is also sort if risk related, but the stakes could be set a bit higher then +/- 20%.
Unburden is probably my favorite so far. Choosing to activate it puts one in the situation that they would want to stay in, if they were to be switched out they would have a useless ability for likely the rest of the game. If a Mon stays in, they could be in a better position to sweep and could be a nuisance to get rid of.