Maybe his/her descendants but not Dark Urge. Because he/she wasn't even born. He/she is handcrafted by bhaal of his own flesh. Mortal part of the god. And Bhaal demonstrate his power over you when you refuse him.
To which they were resurrected after the fact, thus reborn and freed from Bhaal’s influence LOL
All of this is beside the point because Minthara’s decision to support Bhaal’s power is consistent with her goals as a character. If you think that’s strange, that’s fine, I’m just telling you why
I don’t think it’s strange. She can very well ditch DU if she thinks they're too far gone, and she likely will.
There are other Bhaalspawns. I specifically remember hearing DU was initially attacked by Orin and one other Bhaalspawn prior to their memory loss.
