Knowledge Vault [Legends] Nightmare Demon Set: Modern Masters 2015 Type:

Set: Modern Masters 2015 Type: Artifact Creature — Soldier Rarity: Rare Cost: {3} Metalcraft — Etched Champion has protection from all colors as long as you control three or more artifacts

Kari follows no one's rules but her own

Spend this mana only to activate abilities of artifacts

and then there were three

Knowledge Vault [Legends] Nightmare Demon Set: Modern Masters 2015 Type:Set: Legends Type: Artifact Rarity: Rare Cost: {4} {2}, {T}: Exile the top card of your library face down. {0}: Sacrifice Knowledge Vault. If you do, discard your hand, then put all cards exiled with Knowledge Vault into their owner's hand. When Knowledge Vault leaves the battlefield, put all cards exiled with Knowledge Vault into their owner's graveyard.