The Energy Zone only holds one Energy at a time
Its price tag nearly triples that of second-place Sylveon ex, and honestly, it earns it
Boundless Potential Commander aside, I think Walk-In Closet/Forgotten Cellar could grow to encompass many other MTG formats as well
Kelsiens ability to ping a creature and gain experience when it dies is easy to break with a simple Basilisk Collar, and its vigilance means you can declare it as an attacker and still use the effect to one-shot a troublesome blocker
Lightning round: Plane cards are 3.5x5 cards from the Planechase series that modify the battlefield and affect all players
Captain America, First Avenger Captain America, First Avenger is already a strong creature as a 4/4 for 3 mana, clearly an effect of the super soldier serum