Tendrils of the Scarlet Mist (5e Spell)
From D&D Wiki
|V, S, M (a pint of fresh blood from the body of the caster, which the spell consumes, and a ruby worth at least 500 gp)
|Concentration, up to 10 minutes
Brilliant crimson sprays from your outstretched arms, creating a thick scarlet mist interwoven with ethereal translucent veins that pulse rhythmically. The mist initially fills a volume of 3,375 cubic feet, or 27 connected five-foot cubes, with you as the origin. The area covered by the mist is heavily obscured, and the mist itself emits dim, red light for 5 feet. Your awareness spreads throughout the mist, allowing you perceive creatures and objects in the area it occupies as if through blindsight. Whenever a creature enters the mist for the first time or starts its turn inside the mist, you can force that creature to make a Constitution saving throw. If it fails, it takes 4d8 necrotic damage. If it succeeds, it takes half as much. Undead and constructs are unaffected by the mist. The damage dealt by this spell is transferred to a pool of hit points possessed by the red mist. While you are inside the mist, you gain access to the following actions:
Expand. As an action on your turn, you can expend hit points from this pool to expand the mist: 5 hit points to fill a 5-foot cube of space with the mist. The new areas of expanded mist must be connected, and you can only expand up to 1,000 cubic feet this way each turn (8 five-foot cubes). The mist can expand through narrow cracks and gaps in surfaces- if it does so, it costs 1 hit point per 5 feet of crevice. You may also expend your own hit points to fuel this expansion. If a section of mist becomes isolated from you, for example, if a tight door is closed on it, that section of mist withers and disperses completely at the end of your next turn unless it is reconnected before then.
Reclaim. As an action on your turn, you can reabsorb up to 1,000 cubic feet of the mist (up to 8 five-foot cubes), reclaiming 4 hit points to the red mist's pool for every 125 cubic feet.
Bolster. You can use a bonus action to expend hit points from the mist's pool to heal yourself and other creatures of your choice within the mist's area. Divide the hit points you wish to spend among yourself and the chosen creatures. If you heal a creature above its maximum hit points, it gains temporary hit points equal to the remainder. Temporary hit points gained this way can stack, as long as they are obtained throughout the duration of the spell. A creature can possess a maximum amount of 35 temporary hit points gained from this spell. Undead and constructs cannot benefit from this.
Consume. As an action, choose one creature in the red mist's area that isn't an undead or a construct. That creature must make a Constitution saving throw. On a failure, it takes 6d8 + 40 necrotic damage. On a success, it takes half as much. If a creature is reduced to 0 hit points by this effect, it becomes a withered husk and is killed. The damage dealt by this effect is added to the red mist's hit points.
A 5-foot section of mist is destroyed if it takes 15 or more radiant, necrotic, cold, or fire damage in a single turn. If the mist is targeted by an attack or effect that deals psychic damage, you are treated as the target.
The spell ends early if you leave the mist or are no longer connected to it. The mist begins to wither, no longer able to deal damage but still obscuring area and emitting dim light, and it dissipates entirely at the end of your next turn.
At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the necrotic damage dealt by the spell increases by 1d8, the initial area and area that can be expanded or reclaimed each increase by 1,000 cubic feet, and maximum temporary hit points granted by the bolster increases by 5 for each spell slot above 7th. The damage each 5-foot section of mist can take before being destroyed also increases by 5.