Hawk Diesel
Adventurer
So this spell is inspired by the power of the same name presented in the 4e book Heroes of Shadow. It introduces a new mechanic that is a bit weird and not really present in 5e (I think). The wording may be clumsy, and the level of the spell may need adjustment, but I thought I'd put it out there to see what people thought and if the spell could be viable.
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Blood Pulse
3rd-level necromancy
Casting Time: 1 action
Range: 120 feet
Components: V, S, M (your blood)
Duration: 1 round
As part of the spell, you can choose to deal 1d10, 2d10, or 3d10 damage to yourself. This damage cannot be reduced in any way and is necessary to fuel the spell. You slash open a wound upon your wrist with a fingernail, releasing motes of crimson plasma to streak across the battlefield to a point you choose within range. Each creature in a 20-foot-radius sphere centered on that point must make a Constitution saving throw. A target takes 6d6 necrotic damage on a failed save, or half as much damage on a successful one. Until the end of your next turn, any creature that moves through this area takes additional necrotic damage for every 5 feet of movement. This additional damage is equal to the damage you dealt to yourself at the beginning of the spell.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.
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I was also thinking that the player could instead choose to spend up to half their hit dice to fuel the spell, rolling the hit dice and using that towards the secondary damage. But given the potential power and damage of the spell, I thought perhaps the more visceral HP cost was more appropriate.
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Blood Pulse
3rd-level necromancy
Casting Time: 1 action
Range: 120 feet
Components: V, S, M (your blood)
Duration: 1 round
As part of the spell, you can choose to deal 1d10, 2d10, or 3d10 damage to yourself. This damage cannot be reduced in any way and is necessary to fuel the spell. You slash open a wound upon your wrist with a fingernail, releasing motes of crimson plasma to streak across the battlefield to a point you choose within range. Each creature in a 20-foot-radius sphere centered on that point must make a Constitution saving throw. A target takes 6d6 necrotic damage on a failed save, or half as much damage on a successful one. Until the end of your next turn, any creature that moves through this area takes additional necrotic damage for every 5 feet of movement. This additional damage is equal to the damage you dealt to yourself at the beginning of the spell.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.
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I was also thinking that the player could instead choose to spend up to half their hit dice to fuel the spell, rolling the hit dice and using that towards the secondary damage. But given the potential power and damage of the spell, I thought perhaps the more visceral HP cost was more appropriate.