The Erl-King Series by X. Aratare, Raythe Reign

The Erl-King: The Hunt tells the tale of how Alric Koenig acquired his most faithful servant, Jordan Frasier. The manga begins with Alric spinning a familiar story to his son Ethan of how he saved Jordan from a violent animal attack, but the sanitized and edited tale that Ethan receives is far from the truth. The story takes the reader back in time to the 1920s and Germany's Black Forest... moreThe Erl-King: The Hunt tells the tale of how Alric Koenig acquired his most faithful servant, Jordan Frasier. The manga begins with Alric spinning a familiar story to his son Ethan of how he saved Jordan from a violent animal attack, but the sanitized and edited tale that Ethan receives is far from the truth. The story takes the reader back in time to the 1920s and Germany's Black Forest. It shows how Alric is not the rich businessman he appears to be in the current age, but is instead the dread Erl-King. Alric's desire to adapt to the modern world ensnares Jordan in a terrible curse and ensures that the only family his servant will ever have will be the Erl-King's own. This story takes place before the events in "The Erl-King" less

FORBIDDEN LOVE BETWEEN AN IMMORTAL FATHER AND SON. Ethan struggles with his forbidden love for Alric, his king-like father, only to discover that Alric returns his secret passion. But Ethan discovers that Alric is not the man Ethan thought he was; in fact, Alric is not human at all... nor are the loyal retainers Ethan has known since childhood.