Feat: Personalized Poisoning

You developed techniques for discovering a target's weaknesses to poisons using your forensic knowledge. When you study a location that a creature spends a lot of time in, such as a bedroom or office, you learn medical conditions, reactions, or sensitivities that make them susceptible to poisons. Subsequently, whenever you craft an alchemical poison, you can tailor it to a creature you have studied in this way, giving that creature a –2 circumstance penalty to Fortitude saves against the poison and giving other creatures a +2 circumstance bonus to Fortitude saves against it.