Codex Sanguine VI
The Codex Sanguine is an expansion for the Immortal Blood Supplement. Immortal Blood presents a new take on Vampires for Pathfinder 1st Edition¸ specifically within the Aedrenar Campaign Setting. The Rules in Immortal Blood deconstruct the original vampire template¸ and add a seventh new ability score that Vampires can be increased overtime. As this ability score increases¸ these Vampires gain more strength and new powers (some of which are only found in this rules system.)
Even if you don't plan to play Aedrenar¸ any setting that has Vampires as a core focus can benefit from the Codex Sanguine and Immortal Blood. Specifically¸ the Codex Sanguine offers new Blood Powers and feats for Vampires to take!