There are moments in life when someone has a fuel to push forward, maybe even going as far as to burn more than just fuel, especially when that fuel is related to emotional stimuli like revenge.
And naturally for him, after realizing how he should do what he was better at, his initial aim was to get rid of the superheroes or at least the Hero Association.
Given the attack on Spain by Ryken had made him aware of his ability, his target was the Hero Association.
But once they were on the verge of collapse, he switched his motives towards the royal family, trying to destroy them.
Or he nearly did, or at least had reached halfway there, given that, after making the Queen fall for him, he had gripped over one of the strongest heads of the top thirteen families within the archaic Vampire lineage.