In a weekly D&D campaign I’m part of, there’s an NPC called Sanguine, they’re a snake themed individual who was created as a “perfect being”. A close friend of mine adores Sanguine, and as things happened created a Warlock Pact with Sanguine. The DM and us worked together to make this subclass, themed around a snake familiar and purity.
1st-level Sanguine Pact feature
At first level, you gain a reservoir of pure power from Sanguine. You have a number Purity Dice equal to your level in this class that are d6s. You can use one or more die for one of the following features, and you restore your Purity Dice when you finish a short rest.
Manifest Ophis: You summon an ethereal serpent in a space within 60 feet of you as a bonus action that lasts for 1 minute. When a creature starts its turn within 10 feet of the serpent, it must make a Strength Save against your Spell Save DC. On a failure it is grappled, and it takes force damage equal to the number of Purity Dice used to Manifest Ophis and your spellcasting ability modifier. The serpent can only grapple one creature at a time, and you can use your bonus action in order to move it 30 feet.
Gift of Purity: As a bonus action, a creature of your choice that you can see within 60 feet regains hit points equal to the number of Purity Dice used to cast Gift of Purity, adding your spellcasting ability modifier to the amount restored.
1st-level Sanguine Pact feature
At first level, your pact has gifted you with Sanguine’s senses, granting you 30 feet of tremorsense, as well as the ability to talk with serpents.
6th-level Sanguine Pact feature
At 6th level, your body has started to transform to become more like Sanguine’s. Whenever you finish a long rest, you can choose to have resistance to Fire or Cold damage until your next long rest.
6th-level Sanguine Pact feature
At 6th level, your Purity Dice increases to a d8.
Protective Ophis: While Manifest Ophis is active, if a creature within 10 feet of the serpent is attacked, you can use your reaction to spend one or more Purity Dice, adding it to the creature’s AC until the start of their turn.
10th-level Sanguine Pact feature
At 10th level, your Purity Dice increases to a d10.
Snakeskin: You can use your reaction to repeat a saving throw against a condition you are afflicted by, you can also spend one or more Purity Dice, and add the result to the saving throw.
10th-level Sanguine Pact feature
You learn the spell Ophidian’s Black Snakes (Evard’s Black Tentacles). You can cast this spell once per long rest without using a spell slot. You can use one or more Purity Dice and add the total as force damage to creatures affected by this spell.
14th-level Sanguine Pact feature
At 14th level, your Purity Dice increases to a d12.
Improved Aligned Resilience: Your body has become even more like Sanguine’s. Instead of choosing a resistance, you gain immunity to either Cold or Fire damage.
Gift of Snakeskin: As a bonus action, you grant the effects of Snakeskin to a creature of your choice within 60 feet of you. A creature affected in this way, also gains resistance to the damage type currently gained by Aligned Resistance for 1 minute.