The Chained Devil Jailer

You have made a pact with the Chain Devil God, a being from the lower planes of existence who has been prisoner  for the entire existence and whose only goal is to deprive any living form of his freedom. To achieve this, the Chain Devil God helps those who are trapped for some reason and empowers them in exchange of absolute loyalty. 

Expanded Spell List:

Spell Level	Spells
1st	Command, Entangle.
2nd	Web, Earthbind, Chain Control.
3rd	Slow.
4th	Black Tentacles, Freedom of Movement,
5th	Wall of Stone.

Chain Charmer

1st level

When you have contact for the first time with your patron, a black permanent mark with the shape of a chain with a shackle in your left hand palm appears. Since then, you gain the ability to cast at will as an action Chain Control.

Jailer's Mark

1st level

Whenever you restrain, stun, grapple, paralyze or petrify someone, you can mark him with your Jailer's Mark. If someone is marked with this mark, it gets a permanent -1 penalty at every saving throw it rolls for the next minute. Also, if someone hits him with an attack or a spell attack, he can add half your Charisma modifier rounded up to the damage. If the target manages to get rid of the condition, it receives all the dealt damage by Jailer's Mark. You can use this feature once per short rest.

At higher levels: Since level 1, every 5 levels increase the penalty by 1.

Trapped Destiny

6th level

You have discovered how to manipulate the chains of destiny to limit other's capacities and unleash your true abilities. When someone attempts to make a non attack roll against you (Saving throw, Skill confrontation, Skill check...) you can subtract your proficiency bonus to his roll and add it to your roll/Save DC. You can do this once per short rest.

At higher levels: When you reach level 10, you can do it twice per short rest.

Hellish Chains

10th level

When you hit level 10, a red glowing permanent mark of a broken chain appears on your shoulder. Twice per long rest, as a bonus action, you can imbue this mark with your patron's power. Thousands of thin burning hellish chains immediately start growing an covering your entire left arm (some of this thin chains grow from other parts of your body and remain there hanging). While in this form, you gain the following benefits:

• Your chained arm can extend up to 20ft. It can be easily destroyed, but it recovers almost automatically.
• Your grapple reach increases to 20ft. Every round grappled in this state, the target receives 1d12 fire damage.
• You put on fire every flammable object you touch.
• You can grapple two medium targets at the same time and in only one action. You can also grapple one big target.
• You use your Charisma bonus for every roll you make with this arm.

Eternal Demonic Seal

14st level

You have seen so many times the agony of lack of freedom and you have a deep connection with your patron. So is that, that he has showed you the secrets of its own prison. Once every long rest, you can channel your patron's power into a powerful sealing spell. A target within range of sight is caught by the shackles of eternity. While in this state, the target is unconscious. After an entire turn, the target will be able to roll a Charisma Saving throw. If it succeeds, the seal breaks out. If it fails, the target remains in this state and the Save DC is increased by 2. 

This effect can't be avoided by legendary actions, but it can be removed with a Wish spell, 8th level Counter Spell or 7th level Remove Curse.