Rather than killing Michael, Lucifer chooses to show mercy by cutting off Michael's wings, declaring that "everyone deserves a second chance".
Michael attempts to coerce Lucifer into returning to Hell by revealing he orchestrated Dan Espinoza's death specifically to fill Chloe with enough guilt to send her to Hell, where she could be with Lucifer eternally. A Chance at a Happy EndingLucifer : Season 5 Ep...
During the final battle, Michael stabs Chloe with a piece of Zadkiel’s staff. Because she realizes her guilt over Dan's death was a manipulation, she dies guilt-free and ascends to Heaven—the one place Lucifer is strictly banished from under threat of incineration. Rather than killing Michael, Lucifer chooses to show
about why Lucifer didn't actually burn in Heaven. Lucifer Season 5 Ending Explained - Den of Geek Rather than killing Michael