The reason why is because of its effect to make the monster with the highest ATK on the field unaffected by spell effects and its interactions with spell cards that grant ATK
Pokmon Battle-e When scanned into Pokmon Ruby Version or Pokmon Sapphire Version, Pokmon Battle-e cards allowed players to meet special trainers
Unfortunately, the 3-star immersive cards are the rarest pull outside the Crown Rare cards, so this may take some time to complete, but given how many packs it may take to meet Mew's requirements, odds are you may have the others by the time you unlock that one
C Common Black Pendant X SPELL Equip The equipped monster gains 500 ATK
Anything like Brave the Elements that can be used to protect other peoples permanents as well as your own are good options
And the Hades design is so nice its close second to being my favorite, just behind Tigger in the Crows Nest