A demonlord's guidelines on how to get your own very special perfect happy ending

All for One returns in time to rewrite reality as he pleases. Yoichi, engaged by the government as a part of their newly instituted hero program and unaware of this unlikely development, is mildly terrified with the new cold-bloodedness his brother, All for One, appears to have.Or:A self indulgent fic that All for One would probably write because he's a self-deluded two-hundred years old overpowered god complexed moron pretending to be a demon lord who is in denial about his little brother not needing his protection.