I know that I've been bothering all of you about this and I'm really sorry that I am. Which is why I'm probably going to make this the last time I talk about him before I continue planning on his rewritten story. I've finally thought of a great character arc for him, though I'm not sure if it will be any good.

Odium would at first start off as a sinister and hateful vigilante that goes on a journey against the Mane Six and their friends with origins unknown, but would also help/save others from their problems, hardships, and injustices along the way, showing his kinder, more heroic side and willingness to do the right thing for others despite his hateful demeanor.

Once he finds the Mane Six and their friends, he starts to fight them with some struggles, but would still have the advantage with most of them (With mostly the exception of Discord, since he's a reality-warper). However, before he could continue fighting them, Fluttershy and Spike (Who are possibly the only ones who weren't even slightly hurt by him, especially Spike) would brutally lecture him for trying to hurt them for seemingly no reason.

This would cause him to contemplate on the contradiction of both his actions and morality before fleeing in frustration to think to himself alone about what he's doing. While he's having a big moral dilemma, a hallucination of the seer forces him to continue on with his mission if he really wants to make things right for those that were seemingly hurt by the heroes.

While he's continuing his mission against the Mane Six, but still having doubts about what he's doing, he would then eventually be told by the Mane Six and their friends that he's been lied to by the seer. He wouldn't believe them, but after some more physical evidence from them, he becomes so distraught and full of self-loathing that he would run away to his former hometown.

After finding out that he lost literally everything he had in the process of his journey and that most of the crimes that the Mane Six and their friends did were all illusions, as well as how the rest were all fixed, his mind begins to break down in grief, guilt, and even more hatred than before.

The Mane Sid try to help him through his pain, but after something else bad happens that ruins their progress with him, he immediately snaps and relapses back into hating them under the pretense that they were trying to manipulate him in the same way that the seer did, as well as planning on doing something more horrible to him while his guard is down.

While he would try to kill them under his emotional, violent, rage-filled breakdown (while losing his advantage against them due to the Mane Six learning from the first fight, the Plateau Effect, not having his magic-proof staff anymore, and losing his composure and focus while having his breakdown) He would realize for himself how far he's fallen, how monstrous he's become, how the Mane Six really were being sincere, and how he's supposed to help others instead of trying to hurt or kill them. He would then apologize, but genuinely want to be punished for his actions by going to Tartarus for eternity due to thinking that he's unworthy of forgiveness and redemption, at least that easily from them.

Once possibly refused, he would then want to leave Equestria on his own in order to readjust his behavior and make right with the wrongs he's done during his journey against the Mane Six and their friends.

Also, here's his other, more complete character arc from One Stop for Writers:
Odium's Character Arc

What do you think of either character arcs and how do I improve them if there are any issues with them? Let me know by either replying to this thread or via PM. Thank you and have a great day.

7379180
The important question here: did you develop and want to write this story concept and realized you needed the right OC, or did you create this OC first and then decide to come up with a story for him?

7379576
I created the OC first and wanted to write a story for him.