But for a Slime - Chapter 289 - 061.3 - Finding the Last Straw

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.

When I was reborn in South Korea, I wanted to live my life in peace. Pass the activation system, unlock the 'Big Brother' career, obtain the invincible system, and embark on the road to power

The war of gods left the earth no winners, but a broken world.

At home, she was invisible; after marriage, she was a decorative vase; in the end, a sea of flames buried her, and not even her corpse remained. This is the portrait of Han Yuxi’s previous lifetime.

Given a chance at rebirth, she strives to improve herself, wishing only to no longer serve as a foil or a pretty face. Then, she will seek out an exemplary husband and live a life of peace and prosperity. Alas, things turn out contrary to her wishes—she marries a man who bears a blood feud and hatred as deep as the sea.

She turns the world upside-down, but her road to happiness is strewn with setbacks and the sweetness that comes after bitterness.

- Description from Novelupdates