Last best hope - Madeleine Roux

Welcome back to Dungeon Academy, where monsters and creatures train for the dark world that awaits just beyond the Dungeon walls.

Zelli Stormclash and the Danger Club have only one goal: save their friend Bauble from the evil clutches of Elgred Morbide. There's only one problem - the evil machinations of Morbide's selfish plots have come to a head, and the final battle for Dungeon Academy has already begun! Deep beneath the desert, a monstrous dracolich - an evil, undead dragon bent on revenge against everything in her path - is about to be unleashed.

Zelli is no longer on a rescue mission, but a fated quest to save Dungeon Academy, Faern and all the Forgotten Realms. Against impossible odds, the Danger Club - members old and new - must take one last stand together and fight like never before
till the very end.