Swain Support/Jungle?
Hey there, Master Fledgling here.
Swain looks really, really fun from what I have seen and is nigh unstoppable late game. However, he has several items in his kit that make him pop into my head for a Support and Jungler, rather than just terrorizing top and mid lane.
For support, a 2 second, AOE root that isn't minion blocked, several DOTS to keep your spell thief edge constantly proced, a 3 second slow and is flexible enough to work on a cheaper, tanky build over his AP carry, super expensive build.
EDIT: He is also a fan of being around more people while ulting, so 2 v 2 skirmishes favor him.
For jungle, he'd have a rough time till 6, but at which point his clear would be insane. I imagine runeglaive or cinderhulk would work wonders for him, making sense, again, as a crazy carry, an unkillable tank, or somewhere in between.
Cheers and don't mess with crows*,
-MF
(Seriously, they have comparable intelligence to primates and are known to hold grudges.)