You have fundamental medical knowledge, and can perform a ritual that creates a replicant doll of a creature, enabling you to manipulate and damage it's body without laying a finger on it. Battle medics from remote tribes to criminal gangs can follow this archetype to tend to the wounds of their allies and curse their foes with voodoo magic.

Combat Medic

When you choose this archetype at 3rd level, you gain proficiency in the Medicine skill if you don't already have it. You can now use Wisdom (Medicine) checks as a bonus action when attempting to stabilize a creature. This also applies to using a healer's kit to stabilize a creature.

Voodoo Magic

Starting at 3rd level, you can use a free hand to attempt to create a voodoo doll that resembles a creature you can see within 30 ft of you.  The target must make a Charisma saving throw. The DC for this save is 8 + your proficiency bonus + your Wisdom Modifier. The target creature has disadvantage on this saving throw if you have a lock of the creature's hair, a drop of its blood, or any other detached part(s) of the creature's body in your hand, which this ritual consumes regardless of the outcome. If the target fails their saving throw, you successfully create a tiny doll that resembles their visage which appears in your hand. Whilst you have this doll on your person, you have advantage on Charisma (Deception, Persuasion and Intimidation) checks against the target.

You can choose to make an attack roll against the doll. The doll has an AC of 5 and can only be damaged by a weapon attack made by you. If the attack hits, it is considered a sneak attack provided you attack it with a finesse weapon. All the damage dealt to the doll is also dealt to the creature the doll resembles, and the doll disappears. The target does not receive this damage if you don't share the same plane of existence when you attack the doll. The doll also disappears if you move 15 ft. away from it, if you dismiss it as a free action, or if you finish a long rest.

Once a creature has succeeded or failed their saving throw against this feature, you cannot attempt to make another voodoo doll of that creature until 24 hours have passed. You can make a number of voodoo dolls equal to your proficiency modifier, and regain all uses of this feature at the end of a long rest. 

Swift Surgery

At 9th level, you can heal creatures with your bare hands. As an action, you can heal a creature within 5 ft. of you provided it isn't undead or a construct. The healing the creature receives equals half your Sneak Attack dice (rounded down) + your Wisdom modifier; for example, if your Sneak Attack dice is 5d6 you would roll 2d6.

Once a creature has been healed in this way, it cannot receive healing from this feature again until it finishes a long rest.

Voodoo Curse

Starting at 13th level, you can manipulate the souls of your enemies. When you successfully create a voodoo doll of a target, that target can also be either charmed by you or frightened of you if you want them to be as part of the same action. They remain charmed or frightened by you for a minute, or until you end the effect on them as a free action. The creature will no longer be charmed if you or an allied creature does anything harmful to it. Alternatively, if you do not charm or frighten them when you create this doll, you can do so on a subsequent turn as an action, provided the doll is in your hand. You must be on the same plane of existence as the target to affect them in this way.

Once a creature has been charmed or frightened by this feature, you cannot inflict either condition on them again using this feature until you possess a new doll of the same creature. 

Straight for the Heart

By 17th level you have mastery of the voodoo curse. When your attack hits a voodoo doll it is automatically considered a critical hit.