Do you love your daddy and his massive two handed buster sword?

I decided to write this after watching "Do You Love Your Mom and Her Two-Hit Multi-target attacks." The Daddy is really an eldritch abomination trapped in a suit of armour and possible demon lord. The protagonist's real father when she reincarnated into the world was the chosen hero of the land. This is the tale of horrible men and the even worse demon lord that slays them.