Instead, you rotate the card 180 degrees while face up
It doesn't seem like Indoraptor's newfound price tag is going to stick, however
Once you exile a card that meets the discover requirement, you can choose to cast it or put it into your hand, but unless you cant put cards into your hand or cant cast the spell for some reason as the ability is resolving, the card wont remain exiled
For example, if youre building a deck around Urza, Lord High Artificer, you probably want a ton of cheap artifact creatures you can tap for mana, and then big heavy hitters you can cast with his second ability and all of that mana you generate
Conclusion In my opinion, the card itself is playable
Beyond their regular cards, shiny Pokmon Radiant Venusaur, Radiant Charizard and Radiant Blastoise will be featured, though only one of each will appear in a deck at any given time