Here's a breakdown of the set: Holo "BOO" Cards (10 Total): Mewtwo Gengar Gourgeist Mismagius Dusknoir Mimikyu Hatterene Chandelure Darkrai Trevenant Standard Cards (20 Total): Misdreavus Mismagius Nickit Mewtwo Duskull Duskclops Dusknoir Phantump Zubat Murkrow Spinarak Ariados Sinistea Polteageist (Plus other common spooky Pokmon like Shuppet, Banette, etc., depending on the specific bundle).
Beast, Tragic Hero Beast, Tragic Hero has been in more competitive Steel decks than we've had hot dinners
Mana Burn: Cards like Charizard ( Genetic Apex ) require you to remove (or figuratively burn away) their energy in order to attack
Mega Charizard X ex - 125/094 Phantasmal Flames Special Illustration Rare Market Value Loading
Disruptor Flute Marcy: You and I both know someone is going to play this IN RESPONSE to a card already being cast, which is going to be very funny to explain why that doesn't work
The ability can be chunky and mana intensive, so cards with proliferate or something like Venerated Teacher can help mitigate these problems