Junko Enoshima. First, she has self-hatred for specific crimes (like killing her sister or her friends). Of course, this doesn't redeem her because she takes great pleasure in this feeling and she deliberately brings it upon herself.

Second, as we can see from V3's bonus mode and the Ultimate Summer Camp (yes, the events of the games are non-canon, but the characters' personalities are canon) Junko has a deep insecurity - the belief that her very existence is a mistake of the world. Most likely, this is the reason for her desire to impose her philosophy on the whole world - so as not to feel like a freak or a loser. I suspect that her delight in her own execution can also (partly) be explained by the fact that she believes herself to be a monster who deserves punishment.

But, again, this is not explored in detail, and therefore remains ambiguous.

Isaac Ray Peram Westcott enjoys hurting himself so much that he enjoys hurting his loved ones. Does he count for this thread?

I think what Ozai’s wife says to Ozai in the Avatar comics perfectly shows how Ozai really feels about himself.

The Ink Demon, he believes himself to be a mistake and a monster but it isn't enough to correlate with his tragic backstory and it may as well be a manipulation tactic (at least for now)