Infernal Soul

Being in devil's lineage is not entirely uncommon. Most, however, do not inherit the same magnitude of power. Especially in the art of creating magically binding contracts. With your beguiling influence and overwhelming power, the world is yours for the taking. After all, nobody can turn down a good deal. 

Contract Dealer

Starting at 1st level, you've developed a technique to magically bind another to your service. You can spend 10 min drafting a powerful binding contract with a willing creature. You can make the contract last a number of days equal to your sorcerer level. At the end of that time or if you destroy the contract early the effects will end. The contract can give any or all of the following effects, in addition to any other services you agree upon.

• When your contractee makes an attack roll or saving throw, you can use your reaction to add 1d4 to the roll.
• If either you or your contractee takes damage, you can spend 1 sorcery point as a reaction to split the damage evenly between you.
• If either of you fall unconscious, the other will know immediately.

You must be on the same plane for the contract effects to function. Contract effects that require some type of action can combine only be used a number of times equal to your Charisma modifier plus half your sorcerer level (rounded up). You must finish a long rest to use them again.

Once drafted, the contract can be stored in a pocket dimension. Teleporting it there and teleporting it back both take a bonus action. You can only have 1 contract open at a time, if you make a new one, the old one will be destroyed.

Devil's Blood

Also at 1st level, devil's blood helps to bolster and protect you. When calculating your armor class you can use your Charisma modifier in place of your Dexterity modifier. You can change which of them you will use at any time, but you cannot use both. Additionally, you gain resistance to poison damage. You can also speak, read, and write infernal.

Summon Devil

When you reach 6th level in this class, you learn to summon devils from the Nine Hells to aid you. As an action, you can spend up to half your maximum number of sorcery points and an equal number of hit points to summon devils. The devils can have a combine challenge rating equal to or less than the number of sorcery points spent. You can summon up to a number of devils equal to your Charisma modifier. The devils can be summoned for up to 1 hour, but you must maintain concentration on the summons to allow them to remain. If your concentration is ever broken, the devils will return to the Nine Hells 1d6 rounds later. In combat, the devils take their turns immediately after yours. Regardless of how many sorcery points you spend on this ability, you cannot use it again until you finish a long rest.

You can choose to summon the devils already contracted to you in which case they will be obedient to you. Multiple devils can be included in the same contract. If you choose to not form a contract with them, they spawn unaligned with you and act as described in the spell infernal calling. 

Superior Contract

At 14th level, the power that can be manifested through your contract has expanded. You can choose to include the following effects on your contract:

• If either you or your contractor cast a spell with a target of self. You can spend sorcery points equal to the spell level, and a reaction if your contractee cast the spell, to have the spell target both of you. The effects of the spell end on the one who didn't cast the spell if the contract is ended while the spell persists.
• If your contractee is within 60 ft you can use a bonus action to swap places with them. If your contract action limit is reached, this effect can still be activated at the cost of 1 sorcery point.
• If either of you close off your senses, you can see and hear through the other's eyes and ears. You and the contractor must be within 1 mile of each other. This does not count against your number of contract actions per long rest.

Blood for Power

Beginning at 18th level, while under contract, both parties gain the ability to activate a special clause, at a cost. As a bonus action, you or your contractee can expend two of their largest hit die, reducing their current and maximum hit points by the amount rolled to gain a surge of power. For the next minute, they gain the following effects:

• They gain the effects of the haste spell.
• All of their attack and damage rolls gain a bonus equal to your Charisma modifier.
• They have advantage on saving throws made against spells.

Both parties of the contract can only activate this ability once each per long rest. The reduction to maximum hit points is reverted upon finishing a long rest.