I wasn't quite sure where to put this, since it's not exactly a deck idea, but it's pretty much only related to rainbow decks.
I'm sure you've noticed that, what with there being 12 (?) of them, nymphs are pretty common mutants. Now, since they don't retain their superpowers, that usually wouldn't mean much. But thanks to eternity and hourglasses, for as little as the cost of the nymph card + 4 time quanta (eternity + hourglass pull) you can have a nymph instead of a mutant. I found having anti-matter on a stick much more useful than a weak monster with burrow.
It's obviously not something you can rely on as a strategy, but I think that it's a pretty nifty trick when the opportunity presents itself.
