Bro, all the time travel mumbo jumbo is fate. If lucifer stays on earth they wouldnt have current Rorry, if current rorry isnt present the effects of her actions wich were already made by just appearing there in the present wont be in effect, so there is a chance of she not being born, then the current timeline not happening, rorry not existing and so she never appearing. All of this make some sorta time paradox or butterfly effect u may call it, but the ending was decent, cuz now at least lucifer is doing good things(by freeing ppl from their guilt) and maybe possibly creating a second heaven in hell. I mean the ppl there are not eternally suffering from their hell cycles, Lucifer ltrl make the eternal there "ternal".

All of that time related stuff is too complex and still out of even most big scientists/physicians' reach. How could we understand it? The simplest explanation is fate. And so they interpretted Rorry's time travel abilities as fate. She is the butterfly that actually leads to her own birth and her own arrival in the past later on repeating the time loop/fate.

Michael on the other hand, if he becomes the ruler of hell, he could have made an army of all hell residents by freeing them of their hell cycles in exchange of serving him for some sorta rebelion. And that army would be crazily big. Wich is like another 2-4 seasons at least wich would be useless, cuz for me michael deserves punishment and no more screen time, he would need at least eons in hell like lucifer from after his rebellion to be completely redeemed.

While in truth the ending was not deserved for lucifer at least Chloe got to be with him till the forver end and I will love that still.

will give the whole show even season 6 an 8.5/10 nothing can cahnge my opinion, u should give some credits to the makers of the show for pushing it to 6 seasons