The Chain Key & Great Lock

Target: The Great Lock
Keyhole Location: Bottom of the Great Lock
Insertion Time: Action
Turning Time: Bonus Action
Removal Time: Action
Effect: Each time the Key is turned, the user chooses to do one of the following:

• Restrain Creature. A magical chain springs forth from the "mouth" of the Great Lock towards a creature of the user's choice within 30ft. The chosen creature must make a Dexterity Saving Throw, whose DC is determined by the chosen creature's size (see table below). A creature who lacks a solid/physical form automatically succeeds (such as a creature under the effects of the Spell Gaseous Form). On a failure, the chosen creature is Restrained.
  If the user moves in a way that would result in them being more than 30ft. from a creature Restrained in this way, the user must make a Strength Check, whose DC is equal to 10 + the number of creatures being Restrained in this way. On a success, each creature Restrained in this way that would be more than 30ft. away as a result of the movement are dragged 30ft. behind the user.
  Creatures Restrained in this way may use an Action on each of their turns to make a DC 25 Strength Check. On a success, the creature is no longer Restrained and is Immune to the effects of the Great Lock for one minute.
• Release Creature. A creature of the user's choice that is Restrained by the Great Lock is released.

Any time a creature stops being Restrained by the Great Lock, the chain that restrained it is retracted into the "mouth" of the Great Lock.
When the Chain Key is removed from the Great Lock, all creatures Restrained by it are immediately released.

Maker: Tremont Smith
Blood Donor: Tremont's Mother