[@Pudding] I'm still deciding whether I want that to be the case. I don't want to restrain people's creativeness when it comes to their characters.

I'll get more into it in the OOC, but I was thinking that the Sun Prince's have more of an emphasis on personal power and status whilst the Moon Princes have principles steeped in justice and selflessness. The Sun Prince's are more interested in the hunt, destroying shadows as a means to prove their worth in battle. That is not to say that they do not have humanities best interests in mind, but the Moon Prince's are much more righteous; believing their purpose as Magical Boy's is to sacrifice themselves for the sake of the world.

This divide in ideals could relate to how each Magical Boy uses their powers. A Sun Prince might have abilities that increase their combat potential ten fold, allowing them to be more effective at destroying Shadows. A Moon Prince will still have the power to take on Shadows and other Princes, but their abilities might have a more selfless nature to them.

EDIT: But please don't think this is a black or white situation! There can be characters who are more selfish yet still belong to the Moon Princes just as their can be compassionate characters as Sun Princes.