Shackling the Arcane

Sage and her four mates are on a Highway to Hell - literally.
It's Winter Solstice, and the Sage and her guys are heading for a festive visit to their in-laws - who just happen to live in the Underworld.
While it might be cold in the mortal world, Sage is burning up. And it has nothing to do with the fires of Hell. She's in heat, and it's going to take all the demonic efforts of twins Caden and Aiden and the beastly skills of Maddox and Dante to satisfy her.
Can they persuade a reluctant Rowan to bond with Sage too? Because without his help, Sage's insatiable desire might disrupt their trip. And if that trip includes an unexpected invitation to the castle of the Dark Lord himself, they'll need their wits about them.
But when Sage meets Lucifer, her future changes forever.
Sage Fleur may once have been just a university sophomore, with her sights set on joining the prestigious ASF. Now she's Sage Fleur, endangered species, and... Queen?
But as she returns to Oak Mountain to prepare for the new term, even Satan himself can protect her.
They all knew the Resistance wanted to kill the last siren... What they didn't know was that they wanted to take her song.
This is a MMMFMM reverse harem.