These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hand In Hand is a Crowning Moment of Funny all on its own.
Complete Monster: While he was never presented as a nice person beforehand, and considering all the blood he's spilled and continues to spill, even in the story itself, overall, it's when The Lord murders Black Lightning in front of his daughter Thunder, and then calmly tells her she deserves the pain she's feeling for chosing to be a hero that he completely crosses any chance of returning past the Moral Event Horizon.
Magnificent Bastard: The Lord of the Night accomplishes this quite a lot, despite that he was supposed to be dead. One of the prime examples is his plot in Boogeymen IV: Dolorum Ipsum Quia. He not only orchestrated the whole thing, but he did it just so he could watch the Titans kill each other.
Cauterize in Cutting Edge is also one, as he manipulates a whole city and the Titans to accomplish his goals and frame someone for his crimes. And ALMOST gets away with it.
Marty Stu: Noel and Robert sometimes display typical signs of being an author's pet. Sometimes, Robert even calls Noel out on it. They both manage to be well-rounded characters despite it all, however, and at times can be completely subverted.
You could argue that Noel isn't based on the sheer number of flaws this guy has... And while Robert doesn't have as many flaws, he rarely gets big rewards and has no two-sided love interests.
Moral Event Horizon: A few might think the Lord of the Night crossed this when he killed an innocent kid after slaughtering his abusive father and dependent mother. However, he completely cinches it when he not only rejects Murdercrow's love for him, but then immediately implies that he might have been wrong about not having feelings, just so he can stab her in the heart and use her blood (specifically that of a "broken heart") for a ritual to attain god-like powers... and what's worse is that he tells her this just before she dies, even after he's gotten what he needed. Any sympathy he might have had or will gain from the readers will be consistently trumped by this.
Cauterize as well, when he murders Toby Garigan to frame him for his crimes: Toby is an asshole but otherwise innocent. And then there's the fact he essentially sexually molests a female Mook and tries to rape a girl he likes through a brainwashing trick.
Villain Sue: Again, arguable with the Lord of the Night, especially in the later works, such as Heart of Darkness.