Blood Painter (3.5e Feat)
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Blood Painter [Skill, Arcane]
By painting magical diagrams out of your own blood, you can spontaneously cast spells using only your own life energy. This is especial use to casters who prepare spells, or to casters who have run out of spells.
Benefit: At any time, a caster with this feat can cast any spell he knows by painting a magical diagram on a flat 10’ by 10’ surface. This takes one minute per spell level, and deals two points of Constitution damage per spell level to the caster (or loses a like amount of Blood Pool if he has one). If the caster's current Con or Blood Pool is less than double the spell's level, the spell cannot be cast. Any spells cast with this feat are Supernatural effects.