Note: This set cube is still a WIP
This cube is meant to emulate Core Set 2021 booster draft. Core Set 21 was, IMO, the best of the revived Core Sets (M19, M20, M21) for drafting before they did away with the Core Set model (again). It had build-around uncommons, often interesting gameplay, and many good rares that weren't too strong (except for you, Ugin).
That being said, the set had two main problems, those being color imbalance and speed, which I hope to address with my changes.
My methodology is primarily to replace cards with 1-to-1 swaps for other cards of the same color, rarity, and function, if such a change can be made. When appropriate (such as changing an archetype), cards of different function are used.