Manga wo Yomeru Ore ga Sekai Saikyou ~Yometachi to Sugosu Ki mama na Seikatsu~ - Chapter 43: The Strongest Sandbox Game

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

Shao Qing’s only regret in life is that she blindly fell in love with a worthless man. She gave up everything for him, but in exchange was run over by his conniving mistress when she was close to her delivery date. Fortunately, Heaven left her a way. Crimson rain fell from the sky, the end of the world arrived, she resurrected in the morgue and gave birth to a little monster. Turning into a half human, half zombie freak; her son neither human, nor monster; they have no other choice but to rely on zombies’ crystal nuclei to develop their special abilities and continue living. This debt, she’ll definitely repay that cheating couple!

Though he received the skills necessary to teleport across worlds, the king who performed the summoning ritual attempted to trick him into wearing a slavery collar, this annoyed him so he kidnapped the princess and returned to Earth.

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?