Glacial Chasm [From the Vault: Realms] Human Shapeshifter Assassin or the effects of attack

or the effects of attack reaction cards this turn

When Keruga

Set: Collectors' Edition Type: Sorcery Rarity: Uncommon Cost: {2}{G} Destroy target land

Set: Double Masters Type: Artifact Creature — Construct Rarity: Rare Cost: {5} {T}

They found something else

Glacial Chasm [From the Vault: Realms] Human Shapeshifter Assassin or the effects of attackSet: From the Vault: Realms Type: Land Rarity: Mythic Cumulative upkeepPay 2 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) When Glacial Chasm enters the battlefield, sacrifice a land. Creatures you control can't attack. Prevent all damage that would be dealt to you.