Chromatic Armor [Ice Age]Set: Ice Age Type: Enchantment Aura Rarity: Rare Cost: {1}{W}{U} Enchant creature As Chromatic Armor enters the battlefield, choose a color. Chromatic Armor enters the battlefield with a sleight counter on it. Prevent all damage that would be dealt to enchanted creature by sources of the last chosen color. {X}: Put a sleight counter on Chromatic Armor and choose a color. X is the number of sleight counters on Chromatic Armor.

then discard that many cards

Set: Betrayers of Kamigawa Type: Artifact Rarity: Rare Cost: {5} The "legend rule" doesn't apply

Set: Sun & Moon: Forbidden Light Type: Supporter Rarity: Promo

The vedalken embed such urns in their living artifact creations

Set: Neo Destiny 1st Edition Type: Trainer Rarity: Common

Set: Black & White: Legendary Treasures Type: Fighting Rarity: Promo Retreat cost: 1

Set: EX: Crystal Guardians Rarity: Rare

Set: World Championships 2011 Type: Water Rarity: Ultra Rare Retreat cost: Colorless

Set: EX: Team Magma vs Team Aqua Type: Item Rarity: Uncommon

Set: Sun & Moon: Dragon Majesty Type: Dragon Rarity: Secret Rare Retreat cost: Colorless

Set: Eighth Edition Type: Creature — Human Wizard Rarity: Rare Cost: {1}{U}{U} {U}{U}{U}

but it explains much