Grim Surgeon

You are trained in think fast on your feet, in combat to heal injured allies. Your understanding of the body helps you not only to heal your allies, but also injured your enemys.

Combat Medic

You gain Proficiency in the Medicine Skill.
You gain the "Spare the Dying" cantrip, and can cast it as a bonus action.

Transfusion

Once on each of your turns, when you succesfully sneak attack a creature that is not a construct or an undead, you gain temporary hitpoints, equal to twice your proficency bonus.
(Once you reach 13th level with this subclass, the target becomes weakend until the start of your next turn, there movement speed is reduced by 10ft.)

Field Surgeon

After you finish a long rest, roll you sneak attack, and record that number, as an action you can touch a creature within 5ft. of you, you can heal the targeted creature by a number
between one - up to the number you recorded.

Blood Mark

As an action you can roll 2 of your Hit-Dice and touch a creature within 5ft. of you and create a bloodmark at that creature´s body, the creature`s maximum hitpoints are increased by the Hit-Dices you roll, this effect lasts for 8 hours. And as a bonus action you can teleport to an unoccupied space within 5ft. of an marked creature as long as that creature is within 100 feet of you. The number of Blood Mark you can have active at a time is equal to halve your proficency bonus.

Bound by Blood

After a succesful weapon attack you can force a creature (beast or humanoid) to make a wisdom saving throw ( DC 8 + PB + Int. modifier ), on a fail the target is put under the "Dominate Beast" or "Dominate Person" spell effect for 1 min. (does require your concentration as if you where concentrating on a spell), on a successful save you devour hit dice from your target equal to halve your proficency bonus and can heal yourself by rolling them. Once you use this feature you can´t use it again until you finish a long rest.