I've wanted to learn him but I don't even know how to kill with the guy. You simply can't just farm and do good with him but it's hard as hell (to me) to get kills with him. Is anyone here willing to share some tips that could lead to legitimate success with Kassadin? I hate that I've only been successful against feeders.
Uhm, kassadin isn't weak at all. He takes a while to turn on, so you need to stall the game. If you build him like a normal ap mid, he's extremely strong, but the mana costs on rift walk make him oom real fast, so you're basically forced into the tear build. Honestly I wouldn't recommend in normals/solo. It can work, but it's too reliant on team not sucking.
He is basically like Poppy now, crappy early game with a godly late game. Unlike Poppy, though, he has some matchups he can go into where he won't just get dumped on the entire laning phase. He takes a really long time to scale, needing both 
and 
as his core build. After this point he only has up to go. He is very skirmish based and requires small teamfights to get going. Once he does reach late game, he can do better in teamfights since he can basically insta-kill a carry, but until that point, he isn't much of a threat, needing his team to set up his kills for him. He got nerfed incredibly hard because of how overpowering he was, which is why he is in the state he is now. To be able to play him you need to have a lot of game knowledge to barely be able to pull him off and even then, you have a good chance of losing with him.
Kassadin is a late game carry.. he needs at LEAST 2 items before hes strong enough to really kill people. Basically if your team is kill hungry and doesnt wana wait for you to scale, its gana be rough.. the most you can do is cast Q and E and hope to get some assists or KS. After you have 3+ items you should start doing some dmg.
he is weak and has a hard laning, if you really want to use him, you need to passively farm most of the game. keep your distance and last hit with Q
