Okay, here is the big question. Why Entropy?
1. Everything considering rainbow-playing is either in entropy, fire or in 'other'
2. Pentagrams are for demon summoning. And demons fit most in entropy. (And well, entropy has the only card in the game which is actually called "demon")
3. Even (pentagram-drawing) witches would be, in my oppinion, first considered in entropy, and then probably in darkness.
4. I know, that instead of creating chaos, this card more of "removes" chaos. But I guess Supernova is the same as that (no chaos, but easily predictable)
5. Finally, this card just fits perfect when considering SoSe. (As stated before I didn't think of that when I made that card.)
Probably it doesn't fit perfecty into entropy, but it is the only element I think it actually fits in some way. And as I already said, I am still considering making it a duo card with darkness. (But considering SoSe it's probably not likely.)