People joke about Urgot, but the new item . . .

Urgot is the king cheese of cheese at the moment. You want to destroy people? Pick Urgot, get these masteries: http://gameinfo.na.leagueoflegends.com/en/game-info/summoners/masteries/#1nxFKD9cQ.Nu6BltG0.0

Build this:

Sit in the back like a carry. Just pick at people over and over with your q and e. If someone dives you? Ult, shield, kill.

Remember to save your auto attacks! Stay at long q range, and just AA to execute mofos. Also, all of your considerable damage is physical, except for those ridiculously high deathfire touch procs, so you will have crazy sustain.

Alternately: http://gameinfo.na.leagueoflegends.com/en/game-info/summoners/masteries/#1o1oQIz2G.1EN.MlCGUa00

Urgot can be an incredible tank. His passive combined with Runaan's is disgusting. If you ult into the middle of the enemy team, you can keep your passive going on four of them at once (3 from AA, 1 from q). Your team should be able to kill your ult target before your shield even breaks due to all of the stacking damage resistance/reducing effects.