Strong uke

...in his own way.

Yes. Yes, he's strong. With all consequential problems (hilarity ensues). "Just tie me up!"

theoretically

still not sure about that - supposedly he is

Nyup. Really strong. Anyone who uses a swordhand to shut his lover up is strong in my book.

He's the demon-prince.

"Let's not make him angry O.O"

Resilient like a weed and graceful like a butterfly ^^

I consider Olgrius "strong", because he chose to not use his true power and instead tries to negotiate.