Indeed, I'm glad that you were able to realize its homages to last year's Harold jam. I'm glad that one of your entries were implemented due to it being a memorable and unique Harold. I'm sorry you had to beat Shockingly Original Harold down though, that probably was a surprise to you huh.
Yeah. Blackbael/Oni Harold is definitely designed to be the toughest foe. Its an intentional design choice to show that despite Blackbael having the potential to usurp Oldhar, he decided to serve him due to the fact that his son idolized him. And he is a genuinely good father to him despite his appearance. It was never stated in-game but you can tell that sort of thing by feeling.
It's a bit hard for me to put its and it's together in a sentence so I might have to screen a couple of text here and there just in case. Either way, thanks for bringing this to my attention.