Take the talent at 7 (i think) that has your fel flame reduce corruption cooldown. Its really easy to hit your corruptions in team fights, particularly on maps that have objectives that force people to clump in small areas. The best is hitting a corruption on someone dumb enough to run away in a straight line, guaranteed 3 hits + the extra damage from 16. Destruction.
I played one game going with the corruption talents at 1 and 16, and the life steal talents at 7 and 13... i think it was. whatever the life steal steals more and life steal does more damage to enemies below 50%.
it sucks not having the range, but I was mostly using it against enemies who were trying to melee me anyway so it wasn't that needed, and the corruption buff is pretty good.... I didn't feel like I was really giving anything up, healthstone is pretty good, but I think the buffed health steal makes up for it while also giving you more damage.
anyway, I felt like that was best of both worlds, dont have to put all your eggs in the corruption basket and added some deceptive tankiness to the hero... and it also gives a bit more damage early on which if you dont go life steal talents he's really lacking.