[@Lugia] If you want a "Copy Power" What I would do in my personal opinion is that your dragon is able to copy any power he sees and make it his own. However he can only copy one power at a time. Depending on the powers everyone chooses, I haven't looked at the character sheets yet, I'm just about to do that. I may allow him to store 2 or even 3 maximum powers.

Another option if you wanted to go the friend route is bonding. Your dragon forges a strong bond with his friends and when he does he can copy their powers however, in my opinion that could be very op depending on who he befriends so the first opion is better.