My Werepanther System: Starting with Nine Lives - Chapter 8 - 0 TORCH-BEARER

Every novel has a slag character, the one who decides to abandon the protagonist at his lowest, most helpless point, either because he can’t stand the poor guy’s circumstances or for other reasons. But after the protagonist wins his way in life again, they’re the ones who beg with broken sobs to be taken back.

Still, water once spilled can’t be recovered again.

Yet the unlucky Shen Jiayan has been bound to a Water Recovery* System to do just that.

*water recovery – comes from an idiom that means “spilled water can’t be recovered” (English equivalent: there’s no use crying over spilt milk).

- Description from Novelupdates

Yeon-woo had a twin brother who disappeared five years ago. One day, a pocket watch left by his brother returned to his possession. Inside, he found a hidden diary in which was recorded “By the time you hear this, I guess I will be already dead….”

Bearing the supreme Blood of the Emperor, he unlocked the strongest Emperor's Eye!Martial Technique Copying! Bloodthirsty Frenzy! Seeing through illusions! Memory Reading! Burning World Black Flame! Cloning instant movement! Spatial destruction! Unlimited Vision! Time Stasis!…[Chaos Heavenly Emperor] Ling Feng, “With these eyes, I dare to make heaven and earth tremble!”

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

- Description from Novelupdates