Adolin fell prey to Odium's influence in killing Sadeas. It wasn't right in the slightest as it validated Sadeas' arguments and the whimper Sadeas gave before he was killed highlighted the very thing Kaladin learned. If you're going to kill a man, do it in the sunlight with an even playing field.
He's going to continue to feel that influence, but I'm guessing Adolin will be entrusted with an Honorblade as Dalinar will turn a blind eye to Adolin, as per usual.
Adolin's corruption will likely span a few books, but I'm thinking it's inevitable. His foundation isn't solid, even back when he saved the whore in Sadeas' camp, his refusal of her offer was, "Tempting, but my father would kill me." We'll have an evil Adolin, the greatest duelist in Roshar, weilding an honorblade. Perhaps "winning" other honorblades. It's possible he might even become Odium's champion...
Now then, Rysn is a different story, I think she's going to come into a very important role, eventually. The creature she received from the greatshell seems to be the same that Nin uses on Lift. That means she'll be able to negate surgebinding powers. Seems to useful to keep to the interludes.
