Hero father keeps a sword that's got the demon lord's soul on it, and is surprised that the kid he never has time for ends up learning the demon lord's techniques.
Just another example of neglectful parents, and cursed items.
Wait, so can someone explain this to me?
How did he pass that second trial?
I mean, if it was a trial of conviction, sure, this asshat's got that in spades, but heart?
What is it with nobles and their guards not understanding that magical weapons like that have their own minds and chose their wielders.
Also, if the sword actively FLIES AWAY from you, I think the sword doesn't want you.