Down But Not Out

Instead of entering death saving throws, you go into a DBNO state first, you are in a death saving throw state but if someone else heals you with a Medicine 10 check you are brought back up at 20% of your max health, or 5% of you max health if brought back with healing magic (the magic healing goes into temp HP). Once per short rest you can revive yourself to 1 HP with 5% temp HP and you gain 1 level of exhaustion. If the spell ends before you get revived you enter death saving throws with 1 success. All percent health is rounded up and cannot be less than 1. Being hit while down increases the Medicine check by 1 per hit.