The sawbones

You have trained yourself in the science of medicine. The Sawbones learns every inch of physical anatomy, and uses it to heal their allies and hit their enemies where it hurts most. Back-alley doctors, battlefield medics, mad scientists, and other practitioners of all things biological can be Sawbones of one form or another. You heal your allies, harvest parts from dead, monsters, and silence your enemies with deadly precision.

Back-alley medicine

when you take this archetype at 3rd level, you gain proficiency in the Medicine skill. If you are already proficient in Medicine, you can choose another skill to become proficient in. Xou may use your intelligence modifier instead of your wisdom modifier for medicine checks. You can use the bonus action granted by your Cunning Action to administer a potion to creature within 5 feet of you or to make a medicine check to stabilize a dying creature.

Surgons's toolkit

When you take this archetype at 3rd level, you have accumulated a set of tools for combat medicine. While these tolls are on your person, you can use an ation to tend to tje wounds of a creature within 5 feet of you. That creature can spend a number of its Hit Dice up to your intelligence modifier. For each Hit Die spent this way, roll the die and add the creature's constitution modifier to it. The creature regains hit points equal to the total. you can instead choose to end the effects of a poison or disease affecting the target. This expends one Hit Die.

Grim salvage

Starting at 9th level, you can surgically harvest parts from dead monsters and preserve them for future use. You can spend 10 minutes with the corpse of a non-construct creature that has been dead for no longer than 5 days. Make a Medicine check, the DC of which is equal to the CR of the creature +5. On a success, you harvest an organ that does one of the following, so long as the creature had that ability. You may only attempt this ability once per dead creature. The ogan can be used once to replicate the ability of the creature it came from, then it is destroyed. Any damage, save DCs, and modifiers are identical to what they were when the creature was alive.
Poison. You extract the venom a creature uses. If the creature adds poison damage to any of it's attacks, you can harvest a vial of that poison. You may use a bonus action to apply the same poison to one of your weapons. The next time that weapon hits a creature in the next minute, they suffer the effects of that poison.
Breath weapon. You extract the gland responsible for a creature's breath attack. As an action, you can activate the gland and unleash it's deadly payload.
Gaze effect. You extract the eyes or other part a creature uses for gaze ability. As an action, you can activate that organ and use the gaze ability on a creature within range.
Innate spellcasting. You extract a biological element that produces magic. When you harvest this organ, choose a spell of 6th level or lowe from the creature's innate spellcasting list. You can cast that spell through the organ once taking the spell's normal casting time. A wizard can also dissect the organ to transcribe that spell into their spellbook, as if it were a spell scroll.

Adept immunization

At 13th level, you've established a routine of administering small doses of poison to yourself inorder to build up your body's defenses. You are immune to poison and disease. Whenever you make a constitution saving throw, you can add your intelligence modifier to the total

Surgical strikes

At 17th level, your attacks are guided by your anatomical expertise. Whenever you perform a sneak attack on a creature, that creature's maximum hit points are reduced by the amount of damage dealt. That creature can't regain hit points until the start of your next turn. Your attacks are precise and subtle. Whenever you kill a creature, you can do so in a way that makes it seem like they died of natural causes. Using your Grim Salvage ability on the creature negates this effect