They mutate into the creature on top plus all the abilities of the creature under it
At the beginning of your end step, create a green Ooze creature token with "This token's power is equal to the number of card types among cards in your graveyard and its toughness is equal to that number plus 1." At the beginning of your end step, create a green Ooze creature token with "This token's power is equal to the number of card types among cards in your graveyard and its toughness is equal to that number plus 1." Creature - Ooze Ochre Jelly Trample This creature enters with X +1/+1 counters on it
maybe a few spells like Tamiyo's Safekeeping, Tyvar's Stand, Gaea's Gift, Momentous Fall, Shared Summons, Wrap in Vigor some other creatures i didnt think of before: Oracle of Mul Daya, Silverback Elder, Apex Devastator, Cultivator Colossus, Ghalta, Primal Hunger, Cankerbloom, Topiary Stomper, Regal Force For cutting cards, i would just cut cards that arent creatures or synergize with creatures, or dont do alot most of the time
You're also preventing actions, items, songs, and locations from being much of a factor unless they're already in your opponent's hand
Although the ability to equip your opponent's monsters requires the monster to be Fusion summoned, something that without an archetype-specific Fusion card is a little more difficult to pull off, its worth the hassle: the deck relies on having fewer life points than your opponent, while its effect to equip your opponents monsters cant be negated if this condition is fulfilled
This makes it easier to keep up with the hobby in a way that isnt an option for digital TCGs