He comes back with Batman, Superman And the Avengers—merging the two universes is a miracle, as they take on Satan and the Fallen Angels!
It’s a blockbuster without even reading the script!
Lucifer in the (tv) DC Universe has abandoned Hell (it was boring), and now runs a bar in LA, helping the LAPD solve murder cases. His reaction to a bunch of spandex-wearing vigilantes would likely be to compliment them on their fashion sense, flirt shamelessly with Wonder Woman and Black Widow, make a snarky comment or three to Captain America, and ask Batman for advice on a case.
Drinks would be on the house.