Cloud Key (Retro Schematic) (Serialized) [The Brothers' War Retro Artifacts] World Championship 2011 Card Pack immediately after this effect resolves

immediately after this effect resolves

you can Special Summon it if the other "Exosister" monster mentioned on it is on your field or in your GY

Set: Jumpstart 2022 Type: Creature — Hydra Rarity: Mythic Cost: {X}{G}{G} Primordial Hydra enters the battlefield with X +1/+1 counters on it

destroy that monster at the start of the Damage Step (without damage calculation)

Your monsters cannot be destroyed by battle this turn

Cloud Key (Retro Schematic) (Serialized) [The Brothers' War Retro Artifacts] World Championship 2011 Card Pack immediately after this effect resolvesSet: The Brothers' War Retro Artifacts Type: Artifact Rarity: Rare Cost: {3} As Cloud Key enters the battlefield, choose artifact, creature, enchantment, instant, or sorcery. Spells you cast of the chosen type cost {1} less to cast. "A key only unlocks a door. Its wielder must choose whether to cross the threshold." *Hurkyl's Metaphysics, vol. II*