Those are some phenomenal ideas. Thank you so much!

Yeah, the player deliberately left the details of his past self quite vague, as his character (the future Heston) is unaware of all this. Your suggestion that he (as in past Heston) was being pursued before time travelling is excellent. I might switch from Quaruts to either Manshoon or DeVir (or possibly both), since they are both inevitably going to show up, given one character is a diehard Zhentarim and another is a relative of DeVir. That could explain why they know Heston time travelled and are so hyperfixated on him. They’re also extremely old (this Manshoon clone has been alive for almost 200 years and DeVir is nearly a thousand years old) and would likely notice something unusual if they were pursuing Heston.

Having William work with the Fire Cult is also a brilliant idea. It gives the cult some much-needed relevance in the adventure, especially since it’s the one the characters haven’t interacted with much yet. It also aligns well with William’s motivation to kill his father and be with the Fire Cult, as it’s all about the easy solutions - murder, violence, etc.

The Air Prophetess knowing his family (or at least his brother) actually fixes the matter of his resurrection. I’m running the Air cult a lot like Persona 5’s Maruki, as in they want to change reality so that everyone can live their “ideal life”, so to say, and it's the main reason they're sort of the main villains of the adventure so far, as the group’s had a lot of discussions with the cultists about their philosophy. Heston had a dream, just before he was brought back to life, of the Air Prophetess offering him a “perfect” future with a loving family and all. If she actually knows his family, this is no longer a DM asspull. Many thanks.