I agree. Fives is insane once maxed and abilities upgraded. He 4v1 me. My Lumi got targeted by the AI earlier and wiped out of the match. Fives countered and double attacked every move I made. Assist attacks just means he blasts both of the heroes that turn instead of just one. He has huge health and protection, and take forever to kill. His damage may not be rey level per attack, but when he counters every time and double attacks every time with his life pool, it is just too much. I imagine even with my Lumi still love he would wipe the floor with my team.
I don't know if it was bad RNG (the AI smashed my Lumi) or just an OP hero but it was insane. Or maybe my team should just be RG, Fives, Savage, Old Ben or other tanks. But then, how do I kill anything?
Edit: It was my first encounter with the new and improved omega mat and geared up Fives. Wow. Just wow is all I can say.