I use Rhydon in UU and he works well. I run SR, EQ, SE, and Sub. He's great at switching in on Ambipom and Crobat if your lead doesn't handle them well, and threatening back with two 150BP (with STAB) moves and stealth rock. His attack is as high as Absol's, with a move 33% Stronger than Absol's main STAB, so he can hit pretty hard. He can 2HKO Steelix and do a reliable 33% to Slowbro (outspeeding both of them). His solid rock ability allows him to 1v1 a lot of physical tanks and sweepers, since it softens the blow from often un-STAB ground and fighting moves. This offensive capability, along with the defensive benefits of solid rock, sub, and leftovers, and the support benefits of stealth rock, makes him reliably useful in a variety of scenarios, and a good team player.