Well, Papal is indeed "inspired" by Thanos, just as I am sure that Dreadstar takes some inspiration from Mar-Vell, and Syzygy Darklock definitely had some Adam Warlock elements to him.
Go back read Starlin's original Warlock/Magus story, Warlock gets a glimpse of his future and demise. In Syzygy's Origin story, he also gets a glimpse of the future and his demise.
Syz and Adam (in his first run) had vast power but were also limited at the same time.
As to Dreadstar, a trouble warrior with a checkered past. So was Mar-Vell until he jettisoned his past to become the Protector. Also if Dreadstar ever shaved the beard and mustache he'd be a Mar-Vell lookalike.
Dreadstar really felt to me like Starlin wanted to keep using Mar-Vell, Warlock and Thanos but couldn't at the time.
I always thought Dreadstar was a self insert character for Starlin. That was about the time he went circle beard.