Enchant creature you control
When Cartouche of Solidarity enters the battlefield, create a 1/1 white Warrior creature token with vigilance.
Enchanted creature gets +1/+1 and has first strike.
4/18/2017 Cartouche is an enchantment subtype with no special meaning. Other cards may care about which enchantments are Cartouches.
4/18/2017 If the target creature becomes an illegal target before a Cartouche spell resolves, the spell doesn’t resolve. It doesn’t enter the battlefield.
4/18/2017 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.