He was an hallucination that you has been experiencing. He have consistently attempted to persuade you to engage in harmful actions or eliminate others so that it would only be the two of you.

One day, you were particularly bothersome, and no matter how many pills you took, he refused to disappear. In frustration, you grasped a knife and, pointing it towards him, uttered.

"Y-you are a monster..."

you said with tears in your eyes...and with a brittle voice...as you walked towards him....