after reading about vivzie's post-season 2 interview, everyone is, rightfully, assuming that alastor is going to play a villainous role in season 3. mind you, I don't think he is going to be the season's antagonist, I'm pretty sure that's gonna be either lute, lilith or a new character, but still kind of a bad guy.
after all, season 3 is gonna be alastor working on his own free agenda, whatever it may be. his next scheme should involve becoming the most powerful creature in hell, if not the second best next to lucifer. power does come with more opportunities for him to play his sadistic games in hell if there's a guarantee that no one, hellborn, sinner or angel, can beat him.
my bet is that, he's going to take advantage of lucifer, like many have theorized. lilith's return is either going to be joyful or bring loads of drama, lucifer's purpose or role even more questioned. he'll need someone to listen to him, even if the only one offering to hear his depression woes is alastor.
but you know what would be, ironically, great? if instead of hurting him or making it worse, Lucifer genuinely got better. like, not miraculously cured, but good enough to start creating again. lucifer was a creator, a dreamer, an inventor. but he only creates duck-related stuff. he literally helped create the stars! and it would be ironic if alastor accidentally helped him get back his spark.
and alastor? he found himself... weirdly happy about it. charmed even. which made him hate it. so he tried to break lucifer's heart by revealing that it was all a ploy to win his power, his trust. only... lucifer doesn't cry, nor is he mad. he's dismissive, like he's sure alastor is lying about not caring. and alastor is getting even more frustrated, because this idiot king isn't taking him seriously!
cue alastor having a breakdown from caring about someone as stubborn and eternal as lucifer himself.