Any Through the Ages card that you find in your FIN Sealed pool, or that you pick during a FIN draft, is playable in that Limited format , even if they arent Standard-legal
While a Scorpion God deck would likely be constructed to contain numerous effects that put -1/-1 counters on creatures, in case one is ever in need, for three mana, The Scorpion God can put a -1/-1 counter on a creature at any time
Playing it will give your characters the Resist +2 keyword until the start of your next turn, which is almost like making them get large
Keeper of the Nine Gales This has always been my favorite card name
Furthermore, the statement suggests that part of the goal of the Mythic rarity is to avoid making most Mythics tournament playable, which makes sense
For example, if you control four lands named Forest, two named Plains, and one named Swamp, you control three lands with different names