mtg demon support cards of Loathing - Theros Beyond Death you may cast an enchantment spell by paying life equal to its mana value rather than paying its mana cost. Demonic Bargain – MTG Crimson

Ydwen Efreet is not officially Reserved, but its the only non-RL Arabian Nights rare to never see a second printing during the subsequent 30 years

The keywords defender, double strike, equip, fear, first strike, flash, flying, haste, landwalk, lifelink, protection, reach, regeneration, shroud, trample, and vigilance are in Tenth Edition

It's mostly used in the same way that people use Burning Wish and Cunning Wish in Legacy: it can find a potentially game-winning combo piece but also a ton of unique answers like Fracturing Gust, Firespout, Slaughter Games, Flesh / Blood and Wear / Tear

Soulherder, Teleportation Circle, and Thassa, Deep-Dwelling are all cheaper and better, but not every deck can run them or wait until the end step

If Banish to another Universe leaves the battlefield before its triggered ability resolves, the target permanent will not be exiled

In fact, I've played all but 5 cards in the Blue and White genre