Mutate turns two or more creature cards into one permanent, merging their abilities, and usually granting a special benefit when you do so - but the specific wording of the rules generates many edge cases you need to be aware of
Two-color decks that dont have access to much ramp and can afford a few colorless mana sources can make good use of a Myriad Landscape, whereas green decks and 5-color commanders have much less need for something like this
Arguably the only strategy that works exclusively in multiplayer Rakdos decks is chaos
That means cutting cards that dont cleanly fit into either role, or which are redundant versions of effects we have already graveyard decks can easily access huge chunks of their library each game, so variety is more valuable than depth
To make things easier, start by sorting your collection by rarity to find the expensive uncommon, rare, and mythic rare cards