Each card builds on the previous cards that players are playing with, slowly expanding the game in a way that is both fun and manageable
On top of that, Aurora, Dreaming Guardians three strength and five willpower pair with its two lore to make it a solid card by itself, able to likely withstand a few attacks in the early game - especially given that having Shift 3, allowing you to bring it out on top of another Aurora card for a lower ink cost, means you can have it on the field very early on
With only 39 copies originally printed, and only 10 thought to still be in existence, it is considered by many to be one of the rarest cards in the world
Not Gruul
The unique Necron flavor makes even formerly benign artifacts such as Caged Sun feel quite sinister and I think that Warhammer 40,000 fans will see that a lot of thought went into the reflavoring behind these reprints
These sleeves are typically used for valuable and rare cards