Battlefield Medic

Field Medics are among the most selfless and most respected soldiers, often braving great peril and danger to tend to their charges, or evacuate them to where they might be better helped. Tireless and undaunted in the pursuit of their duties, these healers operate expertly and with great skill under the duress and chaos of battlefield conditions. Beyond their obvious capabilities as healers, the cannier of them can employ their knowledge of anatomy and medicine to bolster their likewise notable capacity to inflict harm. 

Field Medicine

When you choose this archetype at 3rd level, you are initiated into the fundamentals of battlefield medicine. Drawing or stowing a Healer's Kit is a free action. As an Action, you can spend one use of a held Healer's Kit to make a Medicine check on a creature within your reach. You have disadvantage on this check if you are targeting yourself. The target regains Hit Points equal to the half check amount plus your fighter level. 
Furthermore, you gain expertise in the Medicine skill.

Intensive Care

At 7th level, your studies have advanced allowing for more complex treatments. You gain the following two abilities: 

• Paramedicine: As a Bonus Action, while you're holding a Healer's Kit, you can make a Medicine check on a creature within your reach. If you do so, choose one effect active on the target which normally ends on a successful Medicine check or Constitution saving throw made at the beginning or end of its turn. The DC of this check is equal to the chosen effect's DC. On a success, the chosen effect ends.

• Field Surgery: As a Bonus Action, while holding a Healer's Kit, you can stabilize one creature within reach, or spend one use of that kit to allow a creature within your reach to spend Hit Die to regain Hit Points as if it had finished a short rest. The target regains Hit Points equal to your Medicine skill modifier for each Hit Die spent this way. You can only use this ability once per rest.

 

Swift Resuscitation

At 10h level, with a physician's skill, you learn how to forceable wrench the dead back into their mortal coil. As an Action, you can spend a use of a held Healer's Kit to make a DC 25 Medicine check targeting a dead creature within your reach. On a success, you can revive the target with 1 Hit Point if it's not an Undead or Construct, has died within the last minute, and didn't die from old age.

Anatomical Studies

At 15th level, you can assess a foe's anatomy with great insight and precision, identifying key weaknesses. As an Action, you can make a Medicine check on a creature you can see with a DC equal to 10 plus the target's distance from you in feet. If you succeed on this check, you know whether the target has at least half its maximum hit points, if it's affected by any diseases or poisons, and any vulnerabilities, immunities, or resistances it has. Furthermore, until the end of your turn, your weapon attacks against the target deal extra damage equal to your Medicine skill modifier. 

Doctorate of Battle

At level 18, your talents for life-saving triage and medicine become legendary. You gain the following benefits:

• Field Surgeon: You can now use your Field Surgery and Swift Resusiciation features as Bonus Actions. You can also use your Field Surgery feature twice between rests.

• Ounce of Prevention: You can spend one use of a Held Healer's Kit to have your Paramedicine feature grant its target advantage on Constitution saving throws for one minute.

• Pound of Cure: A creature revived by your Swift Resusiciation feature regains Hit Points equal to that feature's Medicine check result.