Enchant creature you control
When this Aura enters, target creature can't block this turn.
Enchanted creature gets +1/+1 and has haste. (It can attack and no matter when it came under your control.)
The fifth cartouche is the final affirmation of glory, granted only to the worthy dead.
(18/04/2017)
Each Cartouche is an Aura with "Enchant creature you control." If another player gains control of either the Cartouche or the enchanted creature (but not both), then the Cartouche will be enchanting an illegal permanent and be put into its owner's graveyard as a state-based action.
(18/04/2017)
Cartouche is an enchantment subtype with no special meaning. Other cards may care about which enchantments are Cartouches.
(18/04/2017)
If the target creature becomes an illegal target before a Cartouche spell resolves, the spell doesn't resolve. It doesn't enter the battlefield.
