Who is a good 3150 champion?

if I had to chose which one would get your farther in ranked than the other, it'd have to be Katarina. But if you don't wanna be a bad scrublord then pick Pantheon.

I would recommend Corki though, if you don't have him. He's a really versatile ADC and he's great for poke comps. If it matters, the new jungle has helped out immobile champions because they are less likely to be ganked early game.

Nidalee.

But I don't know if you could handle that much cancer exposure. It might be bad for your long term health.