Grim Guardian | Magic: The Gathering
Formats Grim Guardian is Legal in
Official Oracle Text for Grim Guardian
Official Rulings for Grim Guardian
4/26/2014 : An Aura spell without bestow that has an illegal target when it tries to resolve will be countered and put into its owner’s graveyard. It won’t enter the battlefield and constellation abilities won’t trigger. An Aura spell with bestow won’t be countered this way. It will revert to being an enchantment creature and resolve, entering the battlefield and triggering constellation abilities.
4/26/2014 : When an enchantment enters the battlefield under your control, each constellation ability of permanents you control will trigger. You can put these abilities on the stack in any order. The last ability you put on the stack will be the first one that resolves.