I Became the Tyrant of a Defense Game - Chapter 201

Kawaki, who was born in the dragon vein of a planet (Altana), first met Umibozu who was traveling in the universe, and his girlfriend, Kouka.Later, he came to Earth by accident and met the teacher who affected his life —Yoshida Shouyou.He also met a group of friends. The most conspicuous among the group of friends is a fool with silver hair and naturally curly hair, a short man with purple hair, and a little devil whose catchphrase is “Not Zura, it's Katsura!”Gintama Doujin, not transmigration.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

Majiatisi Lei En, the sole Descendant of the Heroes is the nightmare of his entire town.

The apprentice of a proud Warlock, Lei En works hard to learn his trade unknowingly causing mayhem for those around him.

So when he stood on the tower of the Supreme Wizard, shouting with a heroic flair:

”I want to be the greatest of the alchemist of the Shenji Continent!”

A resounding roar of, “Boos” from the townspeople was the only response he got.

- Description from Novelupdates

Roy died during a war against the Evil God Cult, but somehow, he returned back in time to 30 years in the past where he was just a boy who awaken his summoning magic.