Demon King Reincarnated as the Hero's Child

What is the point of life if you're going to die in the next minute?
I don't know either, but I'd sure like to curse the Hero, the one who's going to kill me, in a way that would last him an eternity.
"Any last words?"
"I'll curse your child! Your harem member no. 1's child! He will forever be weak, ugly, and stupid!"
*
Good, I reincarnated. It's time to get my revenge.
...Wait, isn't this the arms of the really cute harem member no. 1?