Okay, hear me out.
When we get Nari as a follower, he has the immortal trait already in place.
If so, why are his siblings mortal?
I get this whole "god of death" thing, but Narinder's not a god anymore by the time he joins the cult, so he should be more or less in the same boat as the other four.
Do you folks think it's a good idea to give the bishops the trait too? It'd save a few golden necklaces, and would be more consistent.
I see a few possible in-game explanations, with them being gods and all. Since it already takes us two times to defeat them properly, I do think it's plausible to think that the remnants of their power are keeping them alive. Also, since the Lamb has control over death and chooses to spare them and let them join, would it be a stretch to give them immortality?
I do, however, see the merits in keeping them mortal & I'm not super against letting it stay the way it is. It's just an idea!