Sanctum of Eternity [Commander 2019] Rivals of Ixalan you may cast it without

you may cast it without paying its mana cost

Repeat this process until you put a card into your hand or you exile two cards with the same name

Set: Ixalan Prerelease Promos Type: Land Rarity: Rare Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp

we strike first

Set: Magic 2011 Type: Creature — Giant Rarity: Mythic Cost: {4}{G}{G} Trample

Sanctum of Eternity [Commander 2019] Rivals of Ixalan you may cast it withoutSet: Commander 2019 Type: Land Rarity: Rare {T}: Add {C}. {2}, {T}: Return target commander you own from the battlefield to your hand. Activate only during your turn. Come and rest here, beyond the constraints of space and time.