By far the best thing about KRU is how crazy he makes the original Kylo under KRU lead. With all the debuffs and buffs Kylo gets, he has ridiculous survivability. This allows you to pick between which special you want to use rather than constantly using outrage to regain protection. My Kylo is g12 with all g12 gear, and have had titan teams use him for target practice for a solid 2 minutes before it ends in a draw.
Taunting here and there, the stuns, and up to 40k-50k damage with his 2nd special on a stunned enemy are pretty good too.
I run KRU lead, Kylo, Nihilus, GK, and CLS in arena and get the top spot occasionally but usually sit in the teens or 20s, which is the best I've done since the zaul days, so I'm pretty happy with him.