It can be mass artifact animation, turning a bunch of Treasure and Clue tokens into creatures, though its an all-or-nothing ability that affects all your tokens
A general rule that can be used to determine the rarity is based on the rarity symbol on the cards
The land will retain any other types, subtypes, or supertypes it previously had
That said, very little can beat opening a pack and finding these in the early days as the lore of their power had spread quickly among players
It's not hard to see how this deck can snowball out of control, putting more power on the table than your opponents can put up with
It reads like some sort of top-tier mana rock for typal decks, but its worse than the average 2-color Signet or Talisman, and its just strictly worse than Arcane Signet