This idea is pretty heavily lifted from Wildermyth. For those that haven’t played it, one of the features of the game is that you can start later campaigns with legacy characters who retain any weird traits picked up from previous playthroughs even though they were theoretically born in the core village. The fiction is that they’re strongly reincarnated versions of the old heroes, with a vague feeling that adventure is in their very soul. Since the traits from previous adventures frequently involve various obvious physical transformations into elemental or bestial forms, I’m just tickled by the idea that people in town are just like, “Yeah. She was born here. Her arm has always been made of fire.”

This racial option is probably significantly stronger than standard racial options. It trades most of the up-front options for potentially quite a bit of down-the-line upgrades. Honestly, you might do just as well ignoring the ability boost, giving players a full normal race, and letting each PC have a soulmarked progression, letting them play a band of reincarnated former heroes.

Soulmarked

Sometimes, significant deeds in life can bond to a mortal’s very soul, following them from life to life, trying to reach a conclusion. Typically, these are various mystic paths not fully walked. Sometimes, they involve bonds made with powerful entities. For a few, they are significant mistakes worn even through death.

Soulmarked are born as any other child, potentially to a very different race than their past life. Some pop up on completely opposite sides of the planet, while others tend to stay close to the area where their destiny lies. Each has some kind of signifier of previous power, which tends to grow stronger as the child ages. Those that have been reborn multiple times since the marking often seethe with power even as an infant, though it is rarely an immediate danger to the parents.

Likely having dreams of past lives throughout their childhood, soulmarked may or may not formally discover their previous identities. There is never a moment of unlocking names and full memories, but patron entities may wish to regain their service or old allies and enemies may recognize the distinctive powers.

Soulmarked Traits

Your soulmarked character gains a few traits based on parentage, but most of your power becomes from the particular marking source.

Ability Score Increase: Increase one ability score by 2 or two ability scores by 1. These benefits cannot exceed the bonuses provided to members of your parents’ race and subrace (e.g., the child of Lightfoot Halflings could take Dexterity +2 or Dexterity +1 and Charisma +1).

Age: Your aging rate is the same as that of your parents.

Alignment: Depending on the source of the soulmark, there may be some unconscious pull to match the alignment of the entity that granted the mark. However, this is not a guarantee, particularly if you choose to rebel against destiny.

Size: Your size is the same as that of your parents.

Speed: Your base walking speed is 30 feet.

Languages: You speak, read, and write Common and the language of your parents (if your parents are Human, you may choose your extra language).

Subrace: There are several types of soulmarked. You typically gain the first power at first level. The availability of the additional powers is based upon events within the game, and up to your GM to award. Typically these powers remain unlocked for subsequent rebirths, until you reach your full potential.

Energy Soul

Depending on the type of energy, these are often specifically called Firesoul, Frostsoul, Stormsoul, Thundersoul, Acidsoul, Poisonsoul, Shadowsoul, or Sunsoul. As might be evident from the names, this subrace occurs when energy is infused deep into a mortal’s identity. This commonly comes from following the Evocation or Necromancy schools, various forms of bond to dragons or elementals, patronage from certain gods or devils, or even more esoteric sources.

From birth, you would flicker with your particularly energy when particularly upset, though it was seemingly illusory and no danger to those touching you, and your eyes were colored and lit to match. As you became more mature, you learned to manifest your ability to cause harm, and will unlock even more powers as you give more of your soul over to your bond.

Base Power: Manifestation

At first level, you gain a bonus cantrip. If you have a spellcasting class, this becomes a bonus cantrip for that class. If not, it uses your Charisma to generate its attack bonus or saving throw DC.

Depending on your energy type you gain produce flame (Firesoul), ray of frost (Frostsoul), shocking grasp (Stormsoul), thunderclap (Thundersoul), acid splash (Acidsoul), poison spray (Poisonsoul), chill touch (Shadowsoul), or sacred flame (Sunsoul).

Secondary Power: Luminescence

Once you begin to unlock your elemental nature, you can no longer contain its visual signifiers. Subtle patterns along all of your exposed skin constantly crackle or seethe with the energy, though you retain enough control to prevent it from harming your worn or wielded items, or those you touch (though the feel of it is very strange).

You gain Resistance to your energy type. Additionally, you gain the ability listed below:

  • Firesoul: You produce light like a torch, and heat like being near a campfire. You and anyone within five feet of you has advantage on rolls to resist extreme cold.
  • Frostsoul: You can walk without danger of slipping on ice, and blunt nearby heat. You and anyone within five feet of you has advantage on rolls to resist extreme heat.
  • Stormsoul: You are slightly magnetic, and can cause ferrous objects to adhere to your skin, or summon lightweight magnetic objects to you from up to five feet away as if using mage hand.
  • Thundersoul: Constantly suffused in a subtle blanket of noise, you are immune to the Deafened condition caused by sonic attacks, and have advantage to resist it from other sources.
  • Acidsoul: Your natural magic provides a protective influence to all of your equipment against the mild corrosion you exude, granting advantage on any saves to prevent your commonly carried items from being destroyed by any effect.
  • Poisonsoul: You gain advantage to saving throws to resist gaining the Poisoned condition (in addition to your resistance to poison damage).
  • Shadowsoul: You gain advantage on all saving throws to resist the special, non-damaging attack abilities of undead (e.g., life drain, horrifying visage); if the attack does not normally allow a saving throw (e.g., strength drain) you take half the effect you otherwise would.
  • Sunsoul: You produce light like a torch and can produce light like the daylight spell from your body at will.

It is very difficult to hide your nature at this point, and all onlookers have advantage to checks to overcome any disguises (physical or magical) as anything but an energy soul of your type, as wisps of the energy are likely to escape from your control.

Tertiary Power: Emission

You gain a bonus spell. If you have a spellcasting class, this becomes a bonus known spell for that class.

You may additionally (even if if you do not have a spellcasting class) cast the spell once as if with a 3rd level spell slot (if you are not a spellcaster, it is cast using Charisma to generate its attack bonus or saving throw DC). You cannot use the spell again in this way until you take a long rest.

Depending on your energy type you gain scorching ray (Firesoul), snilloc’s snowball swarm (Frostsoul), lightning bolt (Stormsoul), shatter (Thundersoul), melf’s acid arrow (Acidsoul), stinking cloud (Poisonsoul), shadow blade (Shadowsoul), or blinding smite (Sunsoul).

It becomes dangerous to get too close to you. Anyone that isn’t resistant to your energy type cannot spend hit dice to heal during a short rest and does not recover hit points naturally from a long rest if they spend the rest within five feet of you (e.g., sharing a bed, in a small dungeon room, etc.). Bedding that is not specifically enchanted to resist your energy is slowly destroyed by it, usually over the course of a month of sleeping in it. Your clothing deteriorates at a similar rate (though more slowly if you do not wear the same clothing every day), though durable equipment like weapons and armor is only superficially affected, and magical gear is not destroyed.

Ultimate Power: Apotheosis

At the final level, you are almost as much an elemental of your energy type as you are a mortal being, the energy constantly seething from your flesh. You gain Immunity to your energy type. All of your melee attacks add a d4 as additional damage of the energy type. All spells that you cast that deal damage of that energy type are treated as empowered (as per the Sorcerer metamagic ability).

You can no longer disguise your nature physically or with magic. The energy bleeds through any reasonable type of covering, including full plate armor.

Anyone in physical contact with you takes 1 damage of your energy type per round (reduced to 0 with Resistance), including while you are in a grapple. Your life is likely to be quite lonely if you cannot find a resistant partner.