Spoiler Warning: If you have not yet watched Season 4 of Lucifer or the first three episodes of Crisis on Infinite Earths, do not read on until you have.
A couple of months ago, Lucifer star Tom Ellis himself stated that his devilish character would not be making the jump into the Arrowverse for Crisis on Infinite Earths.
However, in Tuesday night’s episode of The Flash, which served as “Part Three” of the crossover, the actor broke his character’s lying rule for a one-scene cameo involving John’s Constantine and Diggle as well as Oliver’s daughter, Mia Smoak.
The scene came about after Mia made it her mission to bring back her father’s soul after resurrecting his body via the Lazarus Pit by means of travelling to Purgatory. The only way Constantine knows how to do this is via assistance from the Devil himself, Lucifer Morningstar, who was revealed to reside on Earth-666, which serves as the main Earth for the television series Lucifer.
However, fans of Lucifer may have been puzzled to not find the Devil ruling over Hell as this is where we left the character at the end of Season 4 earlier in the year.
In an interview with ET after the reveal of his character’s cameo, actor Tom Ellis stated that when we meet Lucifer here, it is during his first five years on Earth after deciding to leave Hell, but before the start of Season 1 of Lucifer where he met Chloe Decker and became a consultant with the LAPD.
Due to Lucifer now being part of the Arrowverse, the show has to abide by the laws set out by their in-canon Multiverse which is while multiple doppelgangers of humans, animals and aliens may exist, there is one Speed Force, one Purgatory, one Heaven, one Hell, one God and one Devil.
Since Constantine became part of the Arrowverse, it also brought in another version of the Devil known as the First of the Fallen, however while that version of the Devil serves as a personification of Satan just as he does in DC Comics, Lucifer Morningstar is the actual genuine Devil of the DC Comics Multiverse.
When asked if there were any future plans for more crossovers with the Arrowverse, Ellis responded with “never say never”.
The final season of Lucifer has not yet received a release date.
Crisis on Infinite Earths concludes with Parts 4 and 5 when the crossover returns on January 14, 2020.