Daemon Lord

The Daemon Lord is a boss in Castlevania: Lords of Shadow - Mirror of Fate, appearing in the plots for Gabriel, Alucard, and Trevor.

Before Mirror of Fate
The Daemon Lord first appears in the prologue, the events of which take place in 1046, 1 year before Lords of Shadow. The Daemon Lord escaped from the Shadow Plane, alongside many demons, sometime prior to the events of the prologue, after the doors to the plane were opened by mysterious means. Gabriel Belmont was dispatched by the Brotherhood of Light, alongside 3 other Brotherhood warriors, to capture the Daemon Lord. The warriors were killed along the way, and the Daemon Lord confronted Gabriel, injuring him, but not before Gabriel gouged out the Daemon Lord's right eye with his Combat Cross. However, Gabriel used the blood from the wound, and a magical device, to capture the Daemon Lord and lock it away.

Events of Mirror of Fate
During Trevor's journey through the castle, a group of witches, seeking a way to defeat Gabriel and claim power for their own, and knowing the Daemon Lord's history with Gabriel, perform a ritual with the device in which the Daemon Lord was trapped, freeing it. The Daemon Lord immediately departs in search of Gabriel, though Trevor stops him, attacking him. The Daemon Lord smells Trevor, and remarks that his blood smells the same as Gabriel. He attacks Trevor, but Trevor manages to defeat it, cutting off its hands and slicing it in half. Trevor walks away, as the Toy Maker watches on, laughing.

The Daemon Lord's remains were assembled and brought back to life by the Toy Maker, as a half-mechanical creature. It encounters Alucard, and, recognizing him as the same one who had killed it, attacks him. It defeats Alucard, burning him in the sunlight and tossing him off of the castle, though Alucard manages to survive, as the Daemon Lord expected.

Alucard later makes his way up to the Resurrection Room and is confronted by the Daemon Lord again, who uses the chamber's beams and electricity against Alucard. Despite this, it is defeated, and thrown into a pit, presumably to its doom.

Trivia

 * When fighting the half-mechanical Daemon Lord as Alucard, the fight can be shortened considerably thanks to a glitch in the game. If you wait until the Daemon Lord fires his laser beam at you, grapple the rail above him to move behind him, and then fire a fully-charged bat projectile at the Daemon Lord just as he's turning around (so the projectile hits his side) he can be stunned early, even with a full health bar. If you grab him at that point you can proceed directly to the QTE where Alucard attempts to rip-off the Daemon Lord's wings while falling down the hole, ending the battle early.
 * The Daemon Lord and Cornell share the same voice actor, Richard Riddings.
 * The Daemon Lord's appearance consisting of a lion head, wings, and a scorpion tail most likely indicates the Daemon Lord is a manticore.
 * The scar over the Daemon Lord's bad eye is absent in his resurrected form.