At the age of 200, he was supposed to accomplish one final great feat and bring his long life to an end… or so he thought. But when he opened his eyes, he had become a baby!Thus begins his second life as Cross Elphid. Unlike his lonely previous existence, he now resolves to live differently—saving the weak and supporting one another through the bonds he forms with many people.A princess who is the strongest of knights, a beautiful young alchemist from a prestigious potion-making family, even a female hero who wields the power of lightning…While spending sweet, heart-fluttering days with these girls, he fully utilizes the 200 years of experience from his past life—and once again dominates the world with his cheat-level abilities!?

Extra chapter from Saiki Kusuo no Ψ Nan volume 12.

When a middle-aged convenience store clerk who lived hiding his dangerous supernatural powers starts working with a cute part-time job girl, that power goes crazy...

Textless, 48th Manga Audition Award for Excellence (Theme: The moment when tears overflowed), in Monthly Comic Zenon

A series of standalone extra chapters published both alongside and after the conclusion of the main series.