There is a certain satisfaction to be found in watching a body go ragdolling through the air, propelled by the strength of his arm. There has always been a particular kind of pleasure to be found in the physical act of deconstruction that cannot be found through other means, like coercing a body's molecules to all go off in different directions. Maybe it's from the effort that goes into it, or maybe it's just pure visceral enjoyment of feeling someone else's viscera on his hands.

Either way: Lucifer enjoys the specific, practical application of violence. He very much enjoys it here.

He does not as much enjoy some eldritch abomination's fist sinking into his vessel's stomach.

This blow, however, he anticipated; not fast enough to block it, but enough to brace for it and avoid being moved backward more than a step or two. Were he human, the strike would've liquified his organs and sent him flying, but poor old Nick here is capable of withstanding so much more abuse with Lucifer's Grace healing and bolstering him. The main thing, though, is that he doesn't have to waste time in getting back up, but can grab a large, splintered chunk of tree and hurl it telekinetically at her; she's quick and slippery, so the best option is to try to pin her down, possibly against one of the sturdier trunks. Possibly pin her literally, if her vessel isn't quite as armored as she thinks.