People are going to recommend that you play Jayce. This is a trick answer as Jayce is actually the worst possible champion you can pick in any situation.
Really though just take someone who has a lot of sustain (vlad, irelia), and preferably some range (vlad, lulu etc)
Honestly lulu is the correct choice for every role.
is that serious or
last time I played ranked match (a patch or two ago) he was perfectly fine and is easy to shitstomp with if you get ahead
Mundo
Support urgot. That passive is a mini exhaust, and armor shredding + slow missles of doom mean a favorable engage whenever you land noxian corrosive charge. And that ult is not too shabby as an engage either.
Just get used to never having enough mana.