Lys Alana Huntmaster [Lorwyn] XY81 you can discard this card

you can discard this card to reduce the damage you take from a battle to 0

Set: Commander 2013 Type: Artifact Rarity: Uncommon Cost: {3} Indestructible

Set: Explorers of Ixalan Type: Enchantment — Aura Rarity: Uncommon Cost: {G} Enchant creature

Set: Force of the Breaker Card type: Continuous Trap Rarity: Ultimate Rare When your opponent declares a direct attack

but if you Tribute Summon this way

Lys Alana Huntmaster [Lorwyn] XY81 you can discard this cardSet: Lorwyn Type: Creature Elf Warrior Rarity: Common Cost: {2}{G}{G} Whenever you cast an Elf spell, you may create a 1 1 green Elf Warrior creature token. From the highest tiers of Dawn's Light Palace to the deepest shade of Wren's Run, the silver notes of the horn shimmer through the air, and all who hear it feel its pull.