pokemon trading card game: mega evolution elite trainer box - Ascended Heroes 1 Basic Energy Pokémon TCG: Mega EvolutionPerfect Order

(2015-08-25) If the non-awaken part of the spell doesn't require a target and you cast the spell for its awaken cost, then the spell won't resolve if the target land you control becomes illegal before the spell resolves (such as due to being destroyed in response to the spell being cast)

They are fairly common and some examples include Mesa Enchantress, Verduran Enchantress, and Enchantress's Presence

And if not a lot of mana, at least a tricksy way to get a few cards from your library into play without paying for them

I'm not entirely sure it makes this case's skeleton enough of a menace for your foe to solve Case of the Stashed Skeleton for you, though

In the case that this is a sudden fad, these boxes are probably overpriced

Mono-Blue decks trying something similar with Arcanis the Omnipotent showed up in Standard around the release of Foundations, but never really took off