New black- and white-bordered cards are legal as of the Prerelease event for the corresponding set, or in the instance of supplemental products, like Commander decks on the release date
Once the card is exiled, you can cast it from exile on a later turn
Hydroid Krasis isn't super flexible since you never want to cast it as a 1/1, but the longer the game goes, the better a threat it becomes
The cards appeal to Magic players, Final Fantasy fans, sealed collectors and people who love premium trading card products
Table of Contents show What Are Adventure Cards in MTG
No, my concern is with a small, but completely different class of cards: those far too powerful to ever be printed in Limited