yeah she is a little bit OP, but you do have to know how to decently user her. If you over-use her abilities when they're not needed (like shunpo or whatever its called, the small jump ability) then you'll often find yourself in bad positioning and die easy (she's fairly squishy until she gets about 6-8+ kills. Can't take in 1v1's with anything that has more than 2k hp)
If you counter her early or if she doesn't get any kills within the first 10-15 mins she's useless for the entire game.
hense the 5 kills game that i won on that list... Didn't get anywhere in that one.