- Alas, Poor Scrappy: Ibriel and Cal, the latter of which happens twice. And Mahu, Zonaquel and Remiel.
- Alternate Character Interpretation: The final scene of the comic is subject to much interpretation. Lucifer leaves the universe to be off by himself for all eternity after a conversation with the Old God about enlightenment. The thing is, Lucifer explictly rejects the comparison and abandons his seeming loved ones. Some have seen this as a metaphor for Lucifer growing up and being mature. Others see it as showing Lucifer is so pathologically immature he can't stand to be around anyone now since contact with other people makes you dependent on them. I.e. he actually got worse rather than better.
- Damsel Scrappy: Rachel and Mona (though Rachel is also this by virtue of being a loud, bratty Jerk Ass). Elaine at first, but she got over it. Subverted with Mazikeen.
- Foe Yay: Rudd and Lys, after the break-up, though they may be more of an ongoing Masochism Tango. Also Lucifer and Izanami at the end.
- And then there's Cestis and Mazikeen.
- Exiled from Continuity: By virtue of being a spinoff of a Exiled from Continuity title, since DC superheroes and the world of Morpheus and Lucifer can't touch or interact without cheapening one or the other. Lucifer has had a few cameos.
- Ho Yay: Jayesh/Karl, which ends up being canon.
- Magnificent Bastard: Lucifer himself, fittingly enough. and God. Almost everything ends up being part of a careful plot by one or the other and when it's not, they spin up a plan B that usually ends up working better.
- Memetic Mutation: Eventually used as part of the "Good Guy Lucifer" advice animals.
- Rescued from the Scrappy Heap: Rachel gets much better in her later appearances.
- Scrappy Mechanic: If you're the sort of person who tries to decipher it, Mazikeen's slurred semi-legible speech quickly becomes very irritating.
- Tear Jerker: About half the death scenes, even when the characters get better, not helped by the large number of woobies; also the relationships between Jayesh and Karl, Rudd and Lys, and Elaine and her foster parents, and the fates of a number of characters you wouldn't expect to miss, or even actively loathe. Let's not even get started on the break-ups.
- Especially the note Karl finds at the end of The Wheels of God story arc in Morningstar. "He knows. He has always known."
- Too Dumb to Live: Sherri and, to a (slightly) lesser extent, Ewan from Volume 2, both of whom are not only stupid enough to climb the large, mysterious building, but also break into it (with Sherri fully believing she's "invited" due to simply having a sixth sense). The building, of course, turns out to belong to Lucifer, and it works out for them about as well as one might expect.
Lucifer: "You came into my house without knocking. And then you prayed to him."