The following homebrew adds a modern option to the Warlock class in 5E TTRPGs. All of the core Warlock class abilities can stay rules as written; see the official 5E System Reference Document (SRD v5) for details. Note: This subclass has not yet gone through playtesting.
Warlock Patron: The Parasite Star
You are bound to a stellar entity that lives by feeding on the lifeforce of others. It may hang visibly in the sky as a faint, pulsing red dwarf, or it exists only as a signal buried in your brain. Its light burns through you, granting the radiance of a dying sun and the hunger of a black hole. You do not worship it. You orbit it.
Expanded Spell List
The Parasite Star lets you choose from an expanded list of spells when you learn a Warlock spell:
1st: Inflict Wounds, Guiding Bolt
2nd: Blindness/Deafness, Heat Metal
3rd: Vampiric Touch, Daylight
4th: Blight, Sickening Radiance
5th: Wall of Light, Enervation
Your spells manifest as radiation flares, ultraviolet burns, or the draining pull of stellar gravity.
Ideas for Pact Gifts and Flavors
* Pact of the Blade: A weapon of condensed light or gravitational distortion, glowing and bending space around it.
* Pact of the Chain: A stellar mote, draining wisp, or tiny black hole familiar that feeds on scraps of light and emotion.
* Pact of the Tome: A fragment of a star’s core, etched with plasma runes that radiate heat when opened.
* Pact of the Talisman: A meteor shard, radioactive pendant, or lens of polarized glass through which the star’s light bleeds.
Level 3: Radiant Hunger
Your patron’s light seeps through your skin and soul.
* When you deal radiant or necrotic damage to a creature, you regain hit points equal to your Charisma modifier (minimum 1).
* You can benefit from this healing a number of times per long rest equal to your proficiency bonus.
* You gain the Light cantrip, if you don’t already know it. The light glows an unsettling hue (sickly white, violet, or blood-red).
* You always know which direction your patron lies in the sky, even through solid barriers or underground.
Level 6: Coronal Flare
You can release a burst of your patron’s energy when harmed. When a creature within 10 feet of you hits you with an attack, you can use your reaction to emit a flare of parasitic light. The attacker must make a Constitution saving throw against your spell save DC. On a failure, they take 2d10 radiant damage and are blinded until the end of their next turn.
You can use this feature a number of times equal to your Charisma modifier (minimum 1), and you regain all expended uses after a long rest.
Level 10: Star’s Eclipse
You exist halfway between light and dark.
* You gain resistance to radiant and necrotic damage.
* When you would be reduced to 0 hit points, you can instead fall into eclipse form — your body flickers into silhouette, your blood replaced with starlight. You drop to 1 HP instead, and gain temporary hit points equal to twice your Warlock level. While in this form (1 minute or until the temp HP are gone), your spells that deal radiant or necrotic damage ignore resistance.
Once you use this feature, you can’t use it again until you finish a long rest.
14th Level: Stellar Consumption
Your patron teaches you to devour life as it does. As an action, you unleash a gravity well of parasitic energy in a 20-foot radius centered on yourself. Each creature of your choice in the area must make a Constitution saving throw.
On a failure, a creature takes 6d8 radiant or necrotic damage (your choice) and you regain hit points equal to half the total damage dealt.
On a success, the creature takes half as much damage and you gain no healing.
After using this feature, you emit dim, reddish light for 1 minute and your eyes glow like dying stars.
You can use this feature once per long rest.