well doesnt lucifer morningstar fit in the eternal power catagory, its him and his bro they have the ability to create and shape multiverses, and YES lucifer did have his own multiverse read lucifer nirvana he said MULTIVERSE not universe.
Lucifer is brilliant, when his father left the throne empty two monsters took his power morningstar used there own power against them thus killing them, if you were to say who were the smartest villains you could say doom for an earth villain, thanos for a cosmic villain and lucifer morningstar for multiple multiverses, because there was at least three multiverses used in the lucifer comics the normal one, his own that he created with the help of his brother AND the new presances the little girl of course they all became one to save the main one.
Dream of the endless says that he's probably the most powerful being in existance and lucifer treated the endless like punks, they were all afraid of him, micheal lucifers brother even told destiny ill take that book from you if i have to. And lucifer burned part of destinys book.
To answer Quanchi.
No he wasn't that impressive.
They made him out to be the ultimate evil, and bad guy who hates libraries, but in actual doing, he was a dud imo.
Lipservice but no real achievements, aside from his off panel handling of Spectre and Mom Teresa.
Narrative and all that tried to sell him, but as far as DC big bads go, Anti-Monitor still holds the title with both lipservice and showings/accomplishments.
Lucifer spanks him. While making fun of his appearance.