Is there really that much difference in times between your own KO's and theirs ? Or even the attacker health (not a “magnitude” of difference). Just you didn’t like seeing 100% ?
Doing another match, especially in Gold, would have gotten you more than coming to make a post (which you're not allowed to show names of someone you accuse of cheating. Just report them in game and be done).
The "no damage taken" is usually a pretty dead giveaway that the individual is cheating. Even block damage would still show as basic/special damage, and you're not getting through either of those fights without that happening. No crit fail from Domino? Seems unlikely.
OP, these cheaters typically get permanent bans. The problem is that they can just go make new accounts and do whatever they want all over again because Kabam can't actually stop them from accessing the game and they're not cheaters until they've already cheated. Unfortunately cheating exists in gaming in the 21st century. Unless Kabam starts requiring anti-cheat software for their mobile version, which seems highly unlikely, it's gonna be a thing that we run into from time to time because people suck.