Is Jergal still a God? Does he have a portfolio? I think he retained some dominion over stuff when he gave his godly power to the dead 3 but I'm not a lore expert and I don't remember.
If he's just a convenient plot device to have easy access to revivify I'm going to be very disappointed.
I think Jergal just gave up his duties, and by gaining those duties the dead three gained the power of the office in a way...but Jergal did not lose his divinity I don't think. Strictly speaking Myrkul technically lost his position as god of the dead a long time ago as ne no longer judges the souls of the dead...there have been a few other gods of the dead since Myrkul, and he even worked for one or two of them but he hasn't lost his powers...he just doesn't go to the office to handle the paperwork anymore. Look D&D lore is messy...just think of it like becoming president or something. There's a lot of powers you gain with the office and a lot of that stuff you retain for life.
I thought the powers of the God comes from their followers are their portfolio/what they rule over, so if you don't rule over anything anymore and don't have followers either I though you couldn't be a god anymore, and I know a lot of this stuff changes with time and between editions so yeah, I don't know xD
Jergal relinquished his divine authority over death to Kelemvor, but he retained a diminished role and continued to serve as a steward of the dead and an observer of fate. He became a subordinate of Kelemvor, taking on the position of a demigod, and his portfolio shifted to encompass record-keeping, bureaucracy, and the inevitability of death.
Seems like Withers could actually be Jergal himself. I think he avoids the question when you asked him about the divine influence you feel around him.