How Did the Demonic Cultivator End Up This Way?

[System] + [Sword Cultivator] [Slow Burn] [Heartbreak, and More Heartbreak]

What turns someone into a demonic cultivator, step by step?

A mentor's distrust, a friend's betrayal, and a lover's tragic death!

I protected all living beings and fought evil spirits and great demons for their sake!

Yet they enjoyed the peaceful world I created for them, right behind me, while pointing fingers at me and condemning me.

If that's how it is, then I'll show you what a true demon is!