Sun Cursed Blood

Sun-Cursed Blood

Potion, very rare

One vial of sun-cursed blood can be substituted for the material components of a spell as long as that component is worth no more than 1,000 gp. The blood is always consumed when casting the spell, even if the standard material component would not be. Targets of the spell automatically fail their first saving throw against it. If a spell cast in this way deals fire or radiant damage, it deals the maximum possible damage when enhanced with this blood. You take 7 (2d6) fire damage plus 7 (2d6) radiant damage as part of casting the spell, but you don’t need to attempt a saving throw to maintain concentration due to this damage.

Alternately, one vial of sun-cursed blood can be applied to a melee or ranged weapon as an action. The affected equipment becomes magical. At the start of each of your turns, roll 2d6. Each time you hit with a weapon attack, that attack deals bonus radiant damage equal to the result, and you take radiant damage equal to half the result (rounded down). These effects last for 1 minute.

Ref: TPKB1 p187