Armor Lock (EFA - A)

You cause the plates and joints of your target's armor to freeze up and become rigid, impeding their movement. Choose a living creature you can see within range wearing armor. That creature must make a Constitution saving throw or its speed is reduced to 10 feet. A target with a flying speed can no longer fly at all, and a target with a climb, burrow, or swim speed has their speed reduced by half. In addition, the target loses any Dexterity bonus to AC for the duration.