Living Spells
You know how you can animate desks and tables? I'd thought the arcane energy of spells themselves were immune to that kind of animation, until I came across one little hut in the middle of nowhere. Inside, a transluscent humanoid form thrummed with deep bass notes, the air tingling with silent pressure, tilting its head towards me, expectantly, as my detect magic was pinging me that there was nothing but evocation magic in front of me...
Magic is pulled from the weave, and spellcasting is reweaving the threads from the weave into new forms. So how is it that such magic can take the form of conscious life? It turns out that when spells are cast, and the thread from the weave is taken from this tapestry in order to be reweaved, there are strange processes, such as proximity to magical dead zones and wild magic zones, that when combined with miraculous timing that doesn't just end up destroying the spell or sending it back to the Weave, have the potential to sever this string directly from the weave. These spells float, disembodied after they are cast. Over time, they accumulate material from the world around them, forming bodies made of both raw magic and various ethereal materials. How they went from being spells without consciousness to having consciousness, no one knows for sure. There are no shortage of theories, however.
Rare Origins
The processes that grant living spells their bodies are not entirely understood, but various arcane investigators have identified their composition. Their appears visually like a layer of mesoglea; a transluscent, elastic material that sparkles and flows as if small rivers of clear liquid are constantly moving around its surface. No organs are present within; instead, a transluscent liquid with the consistency of formaldehyde flows through their body and seems to be required for their function as a conscious creature.
Their coloration depends on the spell they were formed from. A living burning hands might have their transluscent skin and inner liquid might be tinged a bright red and orange, for example. Their eyes sparkle with magical insight shared by only those trained in certain spells.
Lonely Enigmas
These creatures are incredibly rare occurrences, and as a result, they do not typically communities. They are often found alone, in desolate, normally inhospitable places, having long since realized how unusual and alien they are to other humanoids. Their presence attracts investigation and invasive magical procedures from powerful mages. With unique affinities to the spell that they are, however, they are potent users of magic. Some might have contacts in nearby towns that are sympathetic, and who help get access to some luxuries they miss out on normally. Some have made it work. Some try their hardest to disguise their physical appearance, though to mixed results, given how utterly strange they appear.
Magically Minded
With their natural affinity for magic, living spells are most often investigators and researchers. Their very existence, after all, is a mystery even to them. They are inclined to try and find others of their kind, although given their exceeding rarity, these searches have probably so far come up empty. Many living spells have come to the realization that searching for others is futile, and they should make the best of it alone. Maybe if they found each other, their combined insight could help unravel the unique mystery behind each living spell, but as it is, this is an unrealistic dream.
It is, however, a dream. It could be one of many reasons why a living spell seeks adventure. Seeking their origin story, finding others of their kind, finding the person who cast the spell from which they came to be, are all potential reasons why a living spell might stride out into the wider world.
Living Spell Names
Living spells are not typically named by others; instead, they name themselves when they gain the cognitive capacity to recognize the utility of names. As such, most typically name themselves after the spell from which they were formed, like a living thunderwave choosing Thunder as his name. Others might name themselves in explicit contradiction to their origin spell, like a snare spell choosing Free as their name. Others yet might name themselves a name they hear on the wind or from passersby, and might take up a name common to the local cultures nearby.
Living Spell Traits
Your living spell character has the following racial traits.
Ability Score Increase. Increase one ability score by 2 and increase a different one by 1, or increase three different scores by 1.
Age. Living spells slowly dissipate their magical energy over time, losing vitality much like other humanoids. Living spells reach full maturity 1 year after gaining consciousness, and they typically live until the age of 20.
Alignment. Living spells are reserved and paranoid by nature, preferring to stay under the radar. Most living spells are lawful neutral or neutral.
Magical Construct. Made of magic, you are not a humanoid. You are a construct, but you can still benefit from beneficial spells that don't work on constructs, such as cure wounds.
Darkvision. With eyes formed of raw magic, you can see well even in darkness. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.
Size. Living spells vary in size depending on how exactly they were separated by the weave, but the difficulty of the living spell obtaining the ethereal materials that make up their body means that their bodies are typically smaller and much lighter than most other humanoids. Most living spells stand between 3 and 5 feet tall and weigh between 15 and 30 pounds. You can be Small or Medium size, your choice when you choose this race.
Speed. Your base walking speed is 30 feet.
Origin Spell. As a living spell, you were formed via the separation of one particular spell from the weave. Choose one 1st-level spell to be your Origin Spell. You know this spell, you can cast it once without expending a spell slot, and you regain the ability to do so when you finish a short or long rest. When you cast the spell in this way, you cast it at a level equal to your proficiency bonus minus 1. You can also cast the spell using any spell slots or spell points you have of the appropriate level. If your Origin Spell has the ritual tag, you can instead cast it at-will.
Intelligence, Wisdom, or Charisma is your spellcasting ability for this spell when you cast it with this trait (choose when you select this race).
Origin Spell Immunity. You are immune to your origin spell, unless you choose not to be.
Origin Spell Mastery. When you cast your origin spell, the spell cannot be counterspelled. In addition, if a creature you can see within 30 feet of you casts your Origin Spell, you always recognize it, no reaction or Arcana check required, and you can use your reaction to make a contested Arcana check against the creature's Arcana check. On a success, the spell fails.
Origin Resistance. If your Origin Spell deals one or multiple damage types, you can choose one of those damage types. You gain resistance to that damage type. If your Origin Spell does not deal damage, you gain resistance to your choice between force or psychic damage.
Magical Affinity. You gain proficiency in Arcana.
Antimagic Vulnerability. When you start your turn in an area of antimagic, such as antimagic field, or have a dispel magic cast on you, an item you are holding, or a magical effect on you, you must make a Constitution saving throw against the save DC of the effect or else be incapacitated until the end of your next turn. If the effect does not have a DC, the DC is instead 10.
Languages. You can speak, read, and write Common and Primordial. Most living spells learn the local language, and have a natural, innate knowledge of the language of elementals due to their origin in the Weave.
Art Credits
Art (Page 1): Jason Strutz: Living Spells - 2CGaming (Link)
Art (Page 2): Ruan Jia: Vanishness (Link)
Page Stains: /u/flamableconcrete