Masterís Will

Prerequisite(s): Evil Brand, Chosen of Evil or Undead Type.
Benefit: TAs an immediate action, you can beseech the elder evil for assistance. Roll 1d20. If the result of the die roll is an odd number, you gain a +8 bonus on one attack roll, saving throw, ability check, or skill check for 1 round. If the result is even, you take 1 point of damage for each Hit Die or character level you possess. You must make the decision to use this ability before making an attack roll, save, or check.
Source: Elder Evils