Fives is not over powered... If anyone is, it's QGJ. I thought they were going to make faster toons less powerful? Every arena team has him and GS for a reason (annoyingly). Focus the nerfing on those two fast guys with double attacks... They are way OP.
Fives can be handled... Just needs strategy. Don't leave him for last- use your specialty attacks for him and stun when you can.