The Dragon Knight and the Light (The Dragon Knight Series Book 5)

Losing the power to summon his fire-breathing ally, Mercer Eberwolf and his devoted companions must find a way to battle a life-draining enemy who are only becoming stronger and brasher. More allies must be gained, but until traitorous intent is purged from within an empire, it will be a guarded, slow affair.
Soon separated from those who care about him, the desolate dragon knight becomes susceptible to an outsider’s influence, her ever tempting allure of corruption calling to him. For her part, the crystal light of Odet Astor creeps toward purity, but unless she can call forth her family’s divine defender in time, her friend will see no need to resist the ravening darkness.