One of my players thought it would be cool if there was a warlock version of the Child of the Atom sorcerer – a warlock built around radiation, mutation, and nuclear power. Inspired after the party met some salt dryads (stolen directly from Deep Carbon Observatory) who, while chatting to the party, told them they are protected by a pact with the Elemental Lord of Uranium, who sends a heavy metal elemental to scour enemies of the dryads from the planet with nuclear fire. Here you go.
HEAVY METAL WARLOCK
Studying the mystical arts takes a lot of time and effort. Some find this overly onerous or lack the means to learn, so take a shortcut to gain magical power by making a pact with a powerful outsider, becoming their pawn in exchange for powerful abilities. You have made a pact with Gloomium, The Lord of Uranium, an extremely dangerous Elemental Lord who is faithful and generous, if not very forgiving, to those who dedicate themselves to him.
| Level | XP | Proficiency Bonus | Hit Dice | Features | Level Title | Spells Known | Max Spell Level |
| 1st | – | +2 | 1d8 + CON | Eldritch Blast, Gloomium Modification | Contender | 2 | 1st |
| 2nd | 2,000 | +2 | 1d8 + CON | Invocation x2 | Affirmer | 3 | 1st |
| 3rd | 4,000 | +2 | 1d8 + CON | Pact Boon | Claimant | 4 | 2nd |
| 4th | 8,000 | +2 | 1d8 + CON | Ability Score Improvement | Asserter | 5 | 2nd |
| 5th | 16,000 | +3 | 1d8 + CON | Invocation | Avower | 6 | 3rd |
| 6th | 35,000 | +3 | 1d8 + CON | Blade of Gloom | Cultist | 7 | 3rd |
| 7th | 70,000 | +3 | 1d8 + CON | Invocation | Advocate | 8 | 4th |
| 8th | 140,000 | +3 | 1d8 + CON | Ability Score Improvement | Warlock/Witch | 9 | 4th |
| 9th | 300,000 | +4 | 1d8 + CON | Invocation | Master Warlock/Witch | 10 | 5th |
| 10th | 500,000 | +4 | 1d8 + CON | Gloomium Adaption | Arch Warlock/Witch | 11 | 5th |
| 11th+ | Special | – | – | You may spend 100,000 XP to gain a level 11 to 20 5e Warlock class feature or the “Invoke the Fevranzhatavr” pact feature – including additional spell slots, spells known, etc (At the DM’s discretion). | Grand Warlock/Witch | – | – |
PACT OF THE HEAVY METAL PRINCE
The Prince of Uranium seeks to spread his power in his war against the other elements and is happy to recruit eager mortals to serve his labyrinthine plans.
Fiend Expanded Spells
The Heavy Metal Prince lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you and all do radiation damage (where applicable):
| Spell Level | Spells |
|---|---|
|
1st |
burning hands, command, find familiar (always summons a radioactive mephit) |
|
2nd |
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3rd |
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4th |
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|
5th |
Spellcasting
When a warlock casts a spell he makes a spell check to see if he is able to hit the target and manifest the spell correctly. On a natural 1, the warlock loses the use of the spell for the day. The warlock otherwise unlimited use of his spells. When rolling a natural 1, the warlock not only loses the spell but must roll a d6, on a 1 or 6 he also gains patron taint specific to his patron. Patron taint initially starts as a disadvantage but longer-term becomes a positive change as the warlock slowly becomes like his master.
Patron Features
1st Level – Glomium Modification
As part of the Cast a Spell action, you may convert any energy damage you do with your spell into radiation damage. Radiation damage is a special type of poison damage, details here. You can also detect the presence and strength of radiation naturally and instantly when you enter its area of effect. Finally, if you are forced to mutate, you may accept or reject the mutation. This can only happen once per level per day.
6th Level – Blade of Gloom
Pact Weapon: You may conjure any one-handed melee weapon. The ritual to conjure this weapon takes 1 hour. The weapon lasts for one day. Only you have proficiency with this weapon and it counts as magical. You can choose a different weapon each time you cast the ritual. Attacks with this weapon are the same as melee attacks but use your charisma as their attack and damage bonus. The weapon can do the standard damage of its type or poison damage – your choice.
10th Level – Glomium Adaption
You develop a general immunity to poison damage and specific immunity to radiation damage.
14th Level – Invoke the Fevranzhtavr
Calling on the Uranium Lord to smote your enemies you summon the Fevranzhtavr, the protector of the salt dryads and avenging angel of Lord Gloomium. The Fevranzhatavr is a nuclear elemental that will remain for 1 minute and attack enemies you have designated as targets. Once the Fevranzhtavrper has destroyed your enemies, been released by you as a bonus action or the 1-minute duration has passed you gain 5 levels of exhaustion which can only be healed via bed-rest.