I have created a homebrew Paladin subclass, the Oath of Health, based off of the ideas of a Paladin completely devoted to healing and not combat. This was somewhat inspired by the brave doctors and nurses risking their lives against Covid-19 daily to help others. Theses Paladins are sworn to purge disease from the land. My intent is for this to be a party's devoted healer.
Tenets of Health
Cure: Help those who are weak from disease.
Destroy: Work to prevent diseases
You gain Oath spells at the paladin levels listed:
3rd: Cure Wounds, Detect Poison and Disease
5th: Protection From Poison, Lesser Restoration
9th: Remove Curse, Revivify
13th: Aura of Life, Aura of Purity
17th: Greater Restoration, Raise Dead
Idea: Makes them more healing oriented. Allows them to do a lot of very useful utility spells, not to mention raise the dead and the two restoration spells.
When you take this oath at 3rd level, you gain the following two channel divinity options:
Life Transfer: You can use your channel divinity to transfer life from one person to another. As an action, you can make a melee weapon attack against a creature within 5 feet of you. If the creature is undead, you have advantage on the attack roll. If the attack hits, deal additional radiant damage equal to your paladin level + your charisma modifier, and one creature of your choice within 30 feet of you regains hit points equal to the damage dealt.
Idea: A really powerful life transference. It can heal up to 25 HP, which can get a fighter back on their feet after nearly dying. This could be really bad, as a missed attack still depletes channel divinity and wastes their action, though the other channel divinity picks of the slack.
Restore Health: You can use your channel divinity to cause allies to regain health. As an action, you can cause up to 5 creatures within 30 feet of you (including you) that you can see to each regain hit points equal to half your paladin level.
Idea: Another healing power. With this you can turn the tide of a battle or just energize the party. This should be the more powerful of the two channel divinities, but not by much.
Aura of Health
Beginning at 7th level, you and allies within 10 ft. of you have resistance to poison damage and are immune to the poisoned condition. At 18th level, the range of this aura increases to 30 ft. You must be conscious for you and your allies to benefit from this aura.
Idea: A standard 7th level aura, this makes poison really weak. Meant to be used uncommonly, but is potent when used. It may be on the weaker side, as a few races gain this feature already and poison is somewhat uncommon.
Starting at 15th level, when you or an ally within 15 feet of you drops to 0 hit points and is not killed outright, you can choose they drop to 1 hit point instead. You can use this feature a number of times equal to your Charisma modifier, and you regain all expended uses when you finish a long rest.
Idea: Took from the Half-Orc's relentless endurance, this can keep a party alive for another round, potentially winning a fight before they long rest. I think this is balanced and may be a little more powerful, as Relentless Rage requires a saving throw and only applies to them.
At 20th level, you are the master of Healing magic. As an action, you can take on a special healing form for 1 minute. While that form is active, you have the following benefits:
At the start of each of your turns, you and allies within 30 feet regain 5 hit points.
You and all allies you can see are immune to poison damage and resistant to bludgeoning, piercing, and slashing damage from nonmagical attacks.
Once you use this feature, you can’t use it again until you finish a long rest.
Idea: A 20th level capstone transformation gives the party very powerful features that can render them impossible to kill. This is one I am uncertain about, as I have not been able to playtest it. It could be overpowered or underpowered, depending on the campaign.