The Shepherd Alone on the Hill is a Genius Wizard - Chapter 142: The Merman King’s Secret (2)

It is eight or nine years for her to meet her first love again. In the gas station of highway, she sees him walking from the grocery store. She looks at him, not believing what she sees and asks, ‘Do you still remember me?’ He looks at her, with a bottle of mineral water in his hand, and says peacefully, ‘Yes, even if you became ashes.

- 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.