Teiko

The counterpart character to Seki, Teiko is a lot more laid back than his friend, and he and Seki are each other's only friends. He's quite playful and explorative but can be serious when needed. 

He is a shapeshifter and has a dragon form, after loosing his arm both his human and dragon form have prosthetics - If you are drawing him however, don't feel like you have to draw the prosthetic because 1. The reference is out of date and 2. It happens mid story so there is plenty of time where he has both arms.