Former General Is Undead Knight - Volume 2 Heroic Tale of Barreira City, Chapter 1: Great Horse of Nightmare?

Quinn Winter is a young man from another world. One day, he is suddenly chosen to become the new Demon King. But the Demon Kingdom is in big trouble – it's losing a terrible war against the human kingdom called Gran'le.To help his people, Quinn comes up with a risky plan. He will sneak into Gran'le and learn their secrets. But things don’t go as planned. A powerful noble sponsors him, and he ends up joining Heavenward Academy, the top school for training future heroes.At the Academy, there's a big challenge called the Selection. The best students become Paladins – magic knights who fight demons. Quinn doesn’t want to become a Paladin. He is a demon king! But now, he’s stuck in the Selection… and if he wins, he’ll become the very thing he’s supposed to destroy.He started the day badly. Now, things are getting even worse.

Reborn in World of Warcraft : Mastering All Beauty

Mo Ran felt that taking Chu Wanning as his master was a mistake.

His Shizun was just so similar to a cat, while he was like a silly dog.

Dogs and cats were biologically different. The silly dog hadn’t originally intended to put his furry paws out towards that cat.

He originally thought that dogs should be with dogs, like his senior brother, who was beautiful and docile, like a cute Japanese Spitz. They would look so good together.

But after dying and coming back to life, after living two lifetimes, the one he’d brought back to his den both times was that snow-white kitty Shizun that he didn’t even have his eye on at first.

- Description from Novelupdates

Shaymon, the man who has achieved the apex of dark magic, is framed as being a Demon King and is killed.