I still think he’s evil. But his punishments at least happen to be just.
Honestly, I’m wondering if it’s just a world full of horrible people. The barbarian is evil, and everyone he harms is also evil because everyone is evil.
Of the ones I watched, it mostly seemed pretty fair. The leprechaun wanted people’s souls, which would presumably involve infinite torture. Probably not as bad, but the leprechaun probably wasn’t just going to do it once. He did make the Medusa’s imprisonment extra uncomfortable, but it doesn’t seem significantly worse than what she was trying to do to him. It’s not clear what the succubus would do, but I’m guessing she just kills them. And he made her death a little worse than needs be, but ultimately dying is the worst part of it and she’s presumably killing people regularly.
Though the pegasus seems to be an exception. What he was doing probably was on par with the punishment he got, but I don’t think the barbarian knew anything about it. The best I could say is maybe the barbarian didn’t know he was sapient.
Still, he doesn’t seem like a good person.
Call an elf a slur and he’ll hold a grudge for 150 years.
Call a dwarf a slur and he’ll write it down in the Book of Grudges and he and his kin will hold it against you and yours until the grudge is settled.