mask of change booster box chase cards Pokémon sv6 Japanese Display – JapHunter showcasing its Teal Mask alongside other iconic masks and forms as Tera Pokémon ex Pokémon - Mask Of Change

Too situational and too low impact

The deck's main deck building restriction comes from the xenolocking applied by the summon-from-deck searchers "Spright Starter" and "Gigantic Spright", who lock the player into only being able to Special Summon Level/Rank/Link-2 monsters

I have further assumed a distribution of 2 slots to artifacts and colorless cards, 2 each for the five colors, 2 gold cards and either a land slot or an extra gold or artifact/colorless card

Standard Pokmon cards measure 2.5 inches by 3.5 inches (63mm x 88mm)

And to be clear, those are just estimates sourced from the site trying to sell you this stuff