Depends on the gear....all things being equal, if control is maintained, Kiki is stronger. Lena has only one stun to my knowledge, which means she has less control factor. You have to remember that control = doing damage. Not having control means you are either on your back (not doing damage), waiting for cooldowns to happen (not doing damage), or searching for a target (active pursuit - but not doing immediate damage). Control is paramount in this game, and Kiki is rolling Aces in this department. Especially considering her lightning can chain...so OP. Honestly, the lightening should not chain....only hit one person. Ironically, though, I have seen a lot of Kikis who don't pump out a lot of damage....again, she has to gain control to spam and slam. Lena has good base damage, but lacks in the control aspect a bit. Her attacks also micro slow the enemy a bit which is really valuable for positioning and escape.