Opportunistic Sacrifice states that you gain the benefits of the Ritual Sacrifice feat any time you slay someone with magic, melee, or ranged attacks. So, do you get 1 PP for each 4 HP your enemy had before you killed him, as you do when you coup de grace someone with Ritual Sacrifice?
Example: Leif, a scholar/barbarian (who has Opportunistic Sacrifice) gets a melee critical hit on Bob the thief for 51 points of damage. Poor Bob has no armor, and only 31 hit points, so he's pretty dead at -20. Does Leif get 7 PP added to his PP pool, assuming of course his Maximum Power Point pool is big enough?
Example: Leif, a scholar/barbarian (who has Opportunistic Sacrifice) gets a melee critical hit on Bob the thief for 51 points of damage. Poor Bob has no armor, and only 31 hit points, so he's pretty dead at -20. Does Leif get 7 PP added to his PP pool, assuming of course his Maximum Power Point pool is big enough?