In my experience, MKM teaches tight sequencing and rewards thoughtful play while still providing Standard upgrades you will use for months
For all other items, you can return them back, unopened for a store credit
Where in Pokemon, the Video Game, Manga, and even the TV show all have hints of the TCG behind them
(6/6/2025) In the rare case where enough -1/-1 counters are put on Aerith Gainsborough at the same time to make its toughness 0 or less, the number of +1/+1 counters on it before it got those -1/-1 counters will be used to determine the value of X in Aerith Gainsborough's third ability
The tidal wave mentioned earlier is present in this deck too in the form of Inexorable Tide. This is another card that will increase your counters exponentially as it lets you Proliferate every time you cast a spell
I think all the new summons are incredible in general not just in a Counters deck, I think Summon: Yojimbo and Summon: Valefor will be showing up in a bunch of future brews