Cloudstone Curio [Ravnica: City of Guilds] Battle for Zendikar Promos Force of Nature deals 8

Force of Nature deals 8 damage to you unless you pay {G}{G}{G}{G}

or blue creature

Set: Dragons of Tarkir Type: Legendary Creature — Elder Dragon Mythic Cost: {4}{B}{R} Flying

Set: Betrayers of Kamigawa Type: Legendary Artifact — Equipment Rare Cost: {2} Whenever equipped creature deals combat damage

For each of those cards

Cloudstone Curio [Ravnica: City of Guilds] Battle for Zendikar Promos Force of Nature deals 8Set: 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.