Stellar Sovereign

Abandoned by his parents when he was only three months old, Zhang Yun was taken in by a secret assasin organization, called Three-Eyed Owl, where he grew up being forced to learn how to kill and thus survive. Albeit without talent, his stubbornness and tenacity allowed him to survive and show decent results.  One day, he is assigned on a seemingly normal mission to assasinate a rich antique collector. However, the target somehow knew of his arrival beforehand and set up an ambush for Zhang Yun. Surrounded, and without other choice, Zhang Yun escapes into the target's mansion. After finding a strange metal cube, his blood ends up touching it and causing the cube to glow brightly with azure light before it merges with Zhang Yun's soul, causing him to fall unconscious.

After an unknown amount of time, Zhang Yun wakes up in an unknown hall with two people staring at him in shock. The first thing he heard was a soft, beautiful voice...

"This...? This is my soul beast?"