Mortal Coil is book number five in the Skulduggery Pleasant series by Derek Landy
Four Dead Queens is written by Astrid Scholte
United as One is book seven in the Lorien Legacies series by Pittacus Lore (the pseudonym of James Frey and Jobie Hughes)
The Conference of the Birds is book five in the Miss Peregrine's Peculiar Children series by Ransom Riggs
Truly Devious is book one in the Truly Devious series by Maureen Johnson
The School for Good and Evil series is by Soman Chainani