Was it the Abyss Royal Family who didn't want to let him go?
That shouldn't be the case.
The Eye of the Demon God?
It must be that filthy thing, the Eye of the Demon God.
Only the Eye of the Demon God could harm him.
Wasn't it just a matter of throwing a stone at that eye when he left the Abyss?
Did they have to harm him like this?
"Boring struggles for supremacy. I won't kill you, but you shall serve me for a time, let's say... thirty years.
After thirty years, you may leave."
"You want me to work for you?"
Lance pointed to the young dragon behind him with his finger, "Become her sparring partner, feed her tactics for thirty years, and after that, you'll be set free.
It might not even take thirty years, my dragon cub has a good sense of intuition, and if you can improve her strength in a short time, you might leave here earlier."
"Aren't you afraid I'll usurp this dragon cub?"