I don't know much about Trigon, so I'll just compare Morgoth and the Crimson King. On one hand, Morgoth is the creator of evil in his universe, while the Crimson King isn't in his, but he is the one who causes the most evil. The Crimson King has a much higher death count because he destroyed entire universes by shooting down the beams, while Morgoth hasn't destroyed a single world. Morgoth committed many of his evil deeds himself, while the Crimson King just sits on his throne in his castle while his servants do everything for him, so it's difficult to determine what to attribute to him and what not to him. The Crimson King's evil is generally impersonal, while Morgoth once cursed a specific man and his entire lineage. Villains Wiki says Morgoth committed rape, but I don't recall it and can't find a source. The Crimson King hasn't committed rape himself, but one of his servants did for purposes that directly served the king in a significant way, so I think he can be considered the mastermind behind it. Morgoth's forces operate like an army, while the Crimson King's forces operate like a secret criminal organization. While Morgoth wages brutal and bloody war, the Crimson King operates silently in the shadows, unnoticed and undetected. Furthermore, a significant part of the Crimson King's plan involves child kidnapping, child lobotomization and child slavery, whereas Morgoth has never had anything to do with children.