"Aura:
Creatures, permanents, spells, and abilities cost Light quanta for one turn. Discard Halo."
So does this mean that you can save the permanent in your hand for an indefinite period of time before using it?
Are you sure this is the best idea? instead of being able to use it only the turn directly after played?
I'm not saying it should be one way or the other... I have no idea. But I thought I should just bring the question up for thought.