Shadows and Flame, book 4: Eternal Magic
C. N. Crawford2018

Ursula hadn’t expected to return to the Shadow Realm a prisoner, but at least the dungeon reunites her with her old mentor, Kester. That’s only a small consolation when she learns the horrific plans of a shadowy demigod. Plans that involve her.

In order to fight back, she must find her fiancé, Bael. Together, they've got to steal Excalibur from the world's most powerful dragon-shifter.

On her journey, her shocking past is revealed, and Ursula finally learns the truth about herself. But she needs to stay focused. Because if the demigod gets his way with her—the world will come under his nefarious control, and Ursula will be lost in the void forever.