All Outcasts are immune to corruption apart from the Drunk who is always corrupted.
Edit: I'd also like to point out that there just was an update and it makes (among other changes) Alechemist's range more clear/obvious.
They state that they corrupt Villagers but don't explicitly specify that it's only villagers, and it's one of those things that are hard to keep track of during the transition from a friendlies-who-tell-the-truth-and-enemies-who-lie paradigm to a friendly/unfriendly-versus-truthful/lying four-option matrix, deserving of special highlighting I think. I also missed that the Poisoner only targets cards right next to it initially, possibly because the terminology wasn't standardized with the # Cards Away abilities.
I think what I'm saying is that a glossary/rules reminder guide would be helpful. :)