As for the decklist itself, let's take a look and see just what kind of shenanigans we can get into
If you have two copies of Doubling Season, or a Mondrak, Glory Dominus and an Anointed Procession, for each token you create, you actually create a total of four after the effects resolve
With one of the better Abilities out of all Tag Team cards, Mewtwo & Mew's Perfection gives them access to all attacks from their allies on the Bench or in the discard pile
I also love that this is a potential loot engine, giving you some extra ways to put desirable cards into the graveyard for a deck like Soulflayer while creating an alternate threat that can draw some cards when games go late
(Equipment, Auras you control, and counters are modifications.) The +1/+1 counters on Costume Closet won't affect it unless it somehow becomes a creature
The deck loses a lot of steam when Galadriel gets shut down, but as long as we can ramp out two lands with her before she goes it's easy enough to recast her and keep going