Where do you plan on playing these new Crystal cards
Commander decks built around landfall, token swarms, or Bird synergies all treat it as a premium engine piece
Magic: The Gathering|Marvel Super Heroesfeatures four different Commander deck versions
The Convergence of Dominion even helps put cards in your graveyard directly from your library, a mechanic called mill, with its Translocation Protocols ability, milling three cards and building your undead army
Other options in regards to Gruul dragons matter legendary creatures seem quite limited, and the fact Vrondiss, Rage of Ancients and Klauth, Unrivaled Ancient were both in a precon not too long ago likely means they wont show up either
Mana Base New Lands Reliquary Tower is a classic land that could be in almost 100% of the Commander decks nowadays, after all, not everyone likes losing resources due to excess cards in hand