Do Kuros have spirit gems? Are they different from other spirit gems, effects or appearance wise?

Hmm, not too sure what you mean by spirit gems. Is that a reference to something?

But to answer it more blindly, they have Blood Gems. Stones made out of a Kuros’ blood, they often embed it in armor to emphasis their abilities and they’re passed down from generation to generation. Other cultures will seek out these gems to heighten dark spells. Kurosian blood naturally has darkness in it, and within Kurosian culture is usually passed down from generation to generation.

~Weird Hyenas