Walking Through the Abyss

He was originally an orphan born in a mountain temple in the mortal world. The old abbot who educated him passed away; The adopted sister who depended on each other was separated due to the war; The new hope that was finally gained was shattered by a strange accident. His life and death are unknown, uncared for, and uncared for. He became a gray rat in the sewer, a mourning dog on the lonely street, and a falcon with broken wings and broken beak. However, just when he was desperate, the man took the initiative to find him—— And offered to help him get revenge, but there was an offer he couldn't refuse...