Not really. When they appear, you will feel it, and you will be forced to participate. [As far as he's aware.] The ones obtained can be seen in the room at the Tree.

[He peers at Xiao for a long moment in his usually quiet way.]

There may be as many as there are Aspects. The marking you have somewhere on you. There may be more, there may be less. But everyone believes they are the keys to great power. The power required to created a new world, or the power required to bring other worlds back again.

Perhaps their power relies on who is wielding it.