magic core 2021 booster box the Gathering Set foil showcase or alt Magic the Gathering: Core 2021

In terms of upwards potential, you could easily get this deck into Bracket Three without even needing to include any Game Changers

Even-number: Special Summon 1 Doremichord Pendulum Monster with an even-number Pendulum Scale from your face-up Extra Deck

BT10-109 U Option Reinforcement Plug-In O Color White Cost 2 Card Text 1 [Effect] While you have a Tamer in play, you may use this card without meeting its color requirements

Efficient Construction's triggered ability resolves before the spell that caused it to trigger

Imagine turning an army of Saprolings into copies of Augmenter Pugilist with the back side of the card (outside of Commander, of course)