Demonic Skin: If the demon took any damage since its last turn, it gains temporary hit points equal to your proficiency modifier at the start of its turn.

Bond of Demonic Pain

Friend from the Abyss At 1st level you have made a bond with a demon from the depth of the abyss. The demon can look like any demon you want, as long as it uses the stat block above. As you bind your soul with this demonic being, you learn to speak with its tongue and can speak abyssal.

Whip Master When you choose this bond at level 1 you gain proficiency with Whips, additionally when you use a whip it have special properties: You can extends the reach of the whip with demonic fury, the whip gain an additional 5 feet reach, to a total of 15 feet.

The whip is even deadlier in your hands and brings more pain. The whips damage die increases to 1d6. This damage increases to 1d8 when you reach 6th level.

Pain Powered Killing Machine At 3rd level your demon loves the pain, and it evokes a burning rage within it. When you use your action to let your demon use the attack action, as a part of that action you can make a whip attack against your demon. This attack always hit. The damage that the demon takes from the attack is also stored as "Rage", and the next time the demon hits a creature with a melee attack it can add the damage equal to its stored rage, and all the rage is unleashed. The rage can stack up to a number equal to double your Soul Binder level, and all stored damage is lost after 1 minute.

Bloody Veins when you reach level 6 your demons fights best when it is covered in blood. Whenever your demon is below half of its maximum hit points, it gain several benefits: It gains double the amount of temporary hit points from the its "Demonic Skin". When it is hit with your whip, you can choose to give it resistance or vulnerability to the damage, you can do this after you see the roll. It can choose to make its melee attacks deal fire damage instead of its normal.

Painful Commands Starting at level 11, you can command your demon to inflict pain to both its enemies and itself. These commands functions like your "Soul Binder’s Command" and will follow the same rules and uses, you learn two new commands, these will not count toward your total know commands: Painful Retaliation: You command your demon to remember the damage that foes around it inflict on it. Until the end of your next turn, all damage that the demon takes, gets stored as per the use of the "Pain Powered Killing Machine" feature.

You command your demon to remember the damage that foes around it inflict on it. Until the end of your next turn, all damage that the demon takes, gets stored as per the use of the "Pain Powered Killing Machine" feature. Sucker for Pain With this command your demon looses all care for its own health and goes for an all out offensive. Until the start of your next turn your demon deals double damage with all its melee attacks, it also becomes vulnerable to all damage.