MTL - Dark Game, Draw the Talent of Almighty Power at the Beginning - Chapter 127 weird identity choice

In his past incarnation, Lu Xuan was the youngest Celestial Lord that the universe has ever seen!
An accidental rebirth brought him back to a thousand years before, where the Earth had just begun its spiritual reawakening. When he stepped onto the way of cultivation for a second time, he swore to rewrite all injustices suffered in his past life, and defeat all enemies that dare stand in his way!
Let invincibility be his cultivation and the path he treads. In this life, it is his destiny to be invincible!

Li Yubing and Tang Xue were deskmates throughout the whole six years of primary school. After being plagued by Tang Xue for the entirety of this period, Li Yubing saw his chance and broke free with his secondary school selection. With no contact for yet another six years, who knew that Tang Xue and Li Yubing would one day meet again in university…

- Description from Novelupdates

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.