The story
He came back from the dead and took the throne in blood.
Exiled half beast prince Cassian returns, kills his father and seizes the crown, and his first target is Vera, the ice cold former queen who crushed what they had for a crown, married his father and threw him into the beast pit. He installs his stepmother in his bed as his captive and swears to kill Lucian, her son by the dead king. Then the ground moves. His so called half brother carries the same rare beast blood he does, which means Vera has been hiding what Lucian actually is.