Cloudstone Curio [Ravnica: City of Guilds] Champs and States then sacrifice it unless you

then sacrifice it unless you pay its upkeep cost for each age counter on it

{T}: Tap target artifact

If the player does

) When Ancestral Knowledge enters the battlefield

Set: Conspiracy Type: Enchantment Rare Cost: {G} You may play an additional land on each of your turns

Cloudstone Curio [Ravnica: City of Guilds] Champs and States then sacrifice it unless youSet: Ravnica: City of Guilds Type: Artifact Rare Cost: {3} Whenever a nonartifact permanent enters the battlefield under your control, you may return another permanent you control that shares a permanent type with it to its owner's hand. It *wants* to remain a mystery, banishing the curious in favor of less inquisitive company.