Beautiful Doctor Has a Fox Baby - Chapter 2: The Birth of Baby Fox II

A man is reborn into the world of Avatar: The Last Air Bender as a waterbender from Katara's tribe. Best of all, he was the same age as her, and he had a system with him to help.He knows the future and a system that lets him continuously get stronger by completing quests or long-term missions, as well as giving him the ability to copy abilities from others for himself. He will become invincible in the world of Avatar, even more so than the Avatar himself.

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates

Fate, a gatekeeper who had been working for the castle, is beset by a few burdens.

Ethen Cole travels to an era where everyone battles with pets. In a world revived by spiritual energy, danger and madness run rampant. Humanity relies on battle pet masters to establish bases and unite for survival.Before the college entrance examination, Ethen Cole is framed and expelled from school, losing his chance to study at the Battle Pet Academy. Just as he feels despair, the Battle Pet System for battle pets activates.“Ding! The Blue Riolux has evolved into a Emerald eyed Riolux!”From then on, Ethen Cole begins his legendary career as a battle pet master.