Back in the late 1990s, when I first started playing MTG, the Underground Sea was already making waves
Pokemon Trading Card Game Prismatic Evolutions Common Pupitar #48 Pokemon Trading Card Game Prismatic Evolutions Common Pupitar #48 IN STOCK Estimated ship date $0.50 NOTIFY ME WHEN AVAILABLE Email address submitted
But doing so requires the destruction of New Domino City - which he attempts to do using "Meklord Astro Mekanikle", a monster more powerful than every Meklord Emperor
The deck then adds a number of powerful demons with other strong secondary abilities including Aspiring Champion (cast off the top of your deck, direct damage), Bringer (sacrifice/reanimate), Crabomination (steal spells), Demonlord Belzenlok (draw), Doom Whisperer (surveil), Dream Devourer (foretell, buff), Harvester of Souls (draw), Kothophed (draw), Orcus (removal/reanimate), Overseer (removal/creature tokens), Rakdos, Showstopper (removal), etc
Normally this would be used when you have used all the counters off it, giving you some final value
His card stretches the definition of the "Mystic Arcanum" ability, which usually refers to a warlock spell of 6th level or higher