I imagine the following:
will be simple, as they probably aren't that different from USEM. Life might be a bit more trouble if you want it to use Mitosis, but Adrenarush is probably faster. Darkness has Eclipse, and Death has Arsenic, but they aren't too difficult to code.
will be slightly worse, because for air, you probably need to consider Fireflies + UGs and the very least Sky Blitz; for gravity there's Acceleration and Catapult; for time there's extra draws to count (precog, probably hourglasses).
will be a lot more difficult due to Cremations, Cremation targets, Lava Golem's growth from excess Cremation quanta, if any, and phoenixes' rebirth.
And I think the best way to rush with Entropy (although I might be off) involves Improved Mutation... Or maybe just abomidragon spam?