I’m the Bad Guy, Can I Leave?

I possessed the villain, who is torn limb from limb by the protagonist in a fit of inferiority complex. This was a consequence of killing his brother, so I did my best to keep him alive. It was a bonus to get out of the job safely. But how did it happen? The protagonist has completely turned around. He couldn’t let go of me, his lifelong benefactor. “I shouldn’t have left you alone.” No, I’m fine, so please let me leave. Source: NU