Mithril Coat protects a legendary creature while leaving behind a reusable piece of Equipment. Its flash ability lets you cast it in response to removal, and its entry trigger attaches it to a target legendary creature you control. The equipped creature gains indestructible, helping an important commander survive destruction or lethal damage.
This is useful when the commander provides an engine the deck wants to keep on the battlefield. Holding three mana can protect that creature from a destruction spell or a damage-based sweeper without needing to pay the separate equip cost first. The Coat itself is also indestructible, making ordinary artifact destruction a less effective answer to the equipment.
Sram, Senior Edificer can draw a card from casting Coat, and Stoneforge Mystic can find it when the deck needs this kind of protection. Once it is established, the regular equip ability can attach Coat to another creature, including a nonlegendary one. The legendary restriction applies to the entry trigger’s target, not to every future use of the equipment.
Indestructible does not stop exile, sacrifice, or toughness being reduced to zero. The entry ability also targets, so Lightning Greaves can prevent you from attaching Coat to a creature with shroud. Opponents can respond before that attachment resolves. Use Coat when instant-speed protection from destruction matters and when keeping the Equipment afterward gives the deck continuing value, while retaining other answers for removal that indestructible cannot address.
