Francesca Simon 
The Monstrous Child 

A stunning, operatic, epic drama, like no other. Meet Hel, an ordinary teenager – and goddess of the Underworld. Why is life so unfair? Hel tries to make the bets of it, creating gleaming halls in her dark kingdom and welcoming the dead who she is forced to host for eternity. Until eternity itself is threatened.Francesca's first and wonderful foray into teen.