LOL@ earth nymph being weak, 6 turn freeze=weak?
Grey nymphs are fairly good, and a renewable source of aflatoxin is always nice to have, it could very well turn out more useful with more cards, and a double infection is always good. Turqouse is also a nice nymph, could be the solution to the immortal phase recluse deck problem (Packing 6 quints isn't worth it with the 6 recluses, 6 adrens, and then some control). And immortality is always handy. The light nymph however is cannot see ever becoming useful, even with the "Fractal" card Zanz proposed. The only time luciferine is effective is in a rustler deck, where you should never have too much light quanta anyways, and saving up the 9 quanta really isn't worth it, each one could count as 2 life, and light is generally scarce anyway when playing that deck.