As long as this Pokmon is in the Active Spot, your opponent cant play any Pokmon that has an Ability from their hand, except for Team Rockets Pokmon
Although the mechanic of tapping a creature to temporarily change a land has endured, serving most often in domain-oriented sets and decks with cards like Pixie Illusionist, the ability to permanently change a land, which seems like an inevitable development of the concept, comes along a bit later in Magics history, using counters to do it
But, after much discussion, everyone over at SQUARE ENIX decided that invoking the nostalgic love for FINAL FANTASY VI, even in the smallest ways, is the purest version of this collaboration
The official product description also talks about special Japanese-language Mystical Archive cards in Silver Scroll foil, beautiful Borderless cards, and Special Guests cards
Summon: Fenrir Mana acceleration is the name of the game here