Blackstone Code - Chapter 191:

Arakawa Kouki is reincarnated to a Japan with a different history than the Japan he knows with the memories of his previous life still intact. Kouki was discouraged, “Aren’t reincarnation stories supposed to be at some fantasy world filled with swords, magic and elves?!”

Orlax Tirshtain is the villain in the global game [Unification of Empires]. The tyrannical, cold-blooded emperor is a man who slaughtered his own family with his own hands and ascended the throne with their blood—a power-obsessed madman. Despite five years having passed since the game’s release, no one has been able to defeat this lunatic. So, how the hell did I become this damned?????

Xu Jun finally defeated the BOSS–the Dark Demon King, in this stand-alone, virtual reality game. When he wanted to go out to browse Weibo and express his mood, he suddenly encountered a game BUG and immediately passes over to the game world.

He became the man who finally took down the Great Demon King in this world. Gratifying! The attention of millions of people!

……However, he did not know the development of this world was not the same as the game, the Demon King did not die, rather his soul entered into Xu Jun’s body; this Demon King knows of all the stupid things Xu Jun does everyday…….

- Description from Novelupdates

I became the Heavenly Demon’s dog.