Realised I never got around to replying to this. Sorry about that, Christmas kind of happened. Anyway, here goes nothing.
Game balance aside, this card fits being immaterial. It could be normally material (if thats the correct terminology) but I think it makes more sense for it not to be. Because you cant damage something that's millions of lightyears away, or because you cant hurt christmas spirit or any other reason that makes sense.
As for balance, I disagree that this is game-breakingly powerful (or "OP as fk"). The upkeep makes it viable only in a monolight or light heavy duo. In the unupped game, mono light has no real rush cards (peggies at best), and a duo would be pretty slow too Id imagine. When in the upped meta, Archangles become a bigger problem, and quanta generation is easier, but there are more threats to this set up. Basically, I think Im trying to say that since Light isnt an "offensive" element, relying on stalls mostly, this card isnt overly powerful. Then again its 1:40am and I dont know what Im thinking any more.
I would rather nerf it with an ability cost increase than by removing the immaterial status, as Devourer said.