As mentioned the sort of choose your own origin the Baali have make specifics difficult to place. That said here's my various theories.
  • Founders
    • Because of Baali Apostasy it's hard to say what constitutes a founder.
      • Antediluvian - Unknown, Saulot, Tzimisce, or Cappadocius are the most likely possibilities to have sired the three (Nergal, Moloch, Unnamed).
        • Given the Salubri-Baali antipathy and history, along with Saulot's study in the east (which would have exposed him to the Howl of the Devil Tiger Dharma), he seems the best of the likely progenitors. Beckett's Jyhad Diary mentions Ashur
...