The problem with Other creatures is that one nova can cover up to a 12 cost other creature. According to my calculations, if this were a specific element, it would cost 7 quanta or so. However, this needs to be increased by a lot, given this is an Other creature. Since 7 of one specific quanta requires 7 dedicated pillars, this should require 7 quantum pillars, or 21 random quanta.
But I see you made an effort with the Aspectral ability, so that would help some. However, you can still play three of these with one Supernova and still have the low upkeep cost. I would suggest the cost be about 15?