Plus, you can also use it to keep something dying to damage-based removal, just as a burn spell
You gain X life, where X is the greatest number of creatures you control that have a creature type in common
This adds a little bit of originality, some will find uses in competitive play, some collectors would want to get these cards specifically (especially if you give them a cool visual design), and it's such a simple thing to do that having to expend an Ability to achieve the same result (hello, Gallade) is a waste
It takes little work to enable Sage of the Skies, and you can do it as early as turn 3 with the help of cards like Springleaf Drum or Momo, Friendly Flier
That being said, kind of like Tistina before it, this is a strategy that spits out a ton of bodies, limited only by its Extra Deck lock
140 cards total per booster box