if not using Sangromancy this spell is a Conjuration school
Casting Time: 10 Minuets , Range: Self , Components: V (Vocal) - S (Somatic) - M (Material) , Duration: Up to 8 Hours (Concentration)
Special Material: a Sponge soaked in blood
Effect
As part of casting this spell you must expend eight hit dice or the spell automatically fails.
If you do, over the course of the next 1d6 x 5 minutes the sky darkens and thick droplets of blood begin to rain down everywhere within 5 miles of you. Creatures within 5 miles of you gain a level of exhaustion every 10 minutes they are directly exposed to the red rain. Each time a creature gains a level of exhaustion from this effect, it takes 2d10 necrotic damage and has its maximum hit points reduced by an equivalent amount until it is no longer exhausted.
While a creature has any levels of exhaustion caused by this spell, it automatically fails all saving throws against being poisoned or diseased.
Beasts and plant creatures within the area of effect of this spell must succeed on a Wisdom saving throw or be frightened until they have spent 1 minute or longer outside the area of effect of this spell. Mundane plants within the area of effect of this spell wither and die after being exposed to the red rain for at least 10 minutes. For each hour you maintain concentration on this spell, roll one of the hit dice expended in the casting of this spell then total the results at the conclusion of the spell. The total equals the number of days before beasts will willingly return to, and plants can begin to regrow in, the area that was affected by this spell.
At Higher Levels
Lore, some nice lore flavour and/or history