Herald's Horn [Commander 2017] Island Mountain Whenever a land enters the

Whenever a land enters the battlefield under your control

that player gains 3 life

not the battleground

Enchanted creature has protection from red

destroy all non-Wall creatures that player controls that didn't attack this turn

Herald's Horn [Commander 2017] Island Mountain Whenever a land enters theSet: Commander 2017 Type: Artifact Rarity: Uncommon Cost: {3} As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.