Dethrix Drakath, better known as King Dinkelheim Slugwrath, was the ruler of Swordhaven (known as Dreadhaven at the time) until his traitorous knight Sir Alden (now King Alteon) was put up as king after a plan had been made to take him down. He was described as a tyrant so cruel that he was dubbed as the Monster King upon forming an alliance with different monsters and having Underlords ranging from Vampires, Necromancers, Death Knights, Monstrous Warlords, Pyromancers, Mummies that he divided the world with. He also called himself the Champion of Darkness (despite not actually being one himself), as well as the fear feeder and the death mage. When he became king, Dethrix slaughtered many heroes like the Knights of Good, the Frogzard Riders, and other heroes while forced many bards to sing songs about his many victories. All that changed when Alden started slaying his Underlords and slave traders that he was sent to protect. After most of Dethrix' Underlords are either dead or gone into hiding, Dethrix was then dethroned and exiled after losing to Alden, Lynaria, and Valen.
Dethrix later amassed an army to help him continue his conquest of Lore. Scarsgade Keep was one of Dethrix' outposts which got taken over by Alden, Lynaria, and Valen.
Dethrix later had his men attack Ostfort and Highwick and kidnapped Lynaria with plans to kill her at Ebonslate Fortress to end her threat to him. Valen (who would later become Sepulchure) defeated him with the powers of darkness that he acquired through the DoomKnight armor that was being kept hidden in the Guardian Tower after a failed first attempt to do so. Sepulchure hurled him against the wall of Lynaria's cell, stabbed him through the chest with the Doomblade, and finally ripped out Dethrix's heart, killing him instantly, all to make sure that he would never threaten anyone again.
Dethrix also has an important part in AQW's main storyline, as he was Drakath's father who gave him a Chaos Eye amulet before his battle with Alden, Lynaria, and Valen. The Chaos Eye amulet that Dethrix provided his son later gave Drakath his chaos powers and transformed him into the Champion of Chaos who sought to free his master, the Queen of Monsters. According to Drakath's journal in Crownsreach, it was after Dethrix's initial defeat that King Alteon made it a crime to speak the name of Dethrix Drakath himself, which also, from Drakath's perspective, made it a crime to speak Drakath's own name.
- His cape resembles two pairs of pointy spider legs, and his helmet resembles a horned bat's head.
- He wields an axe when he goes into battle. Said axe later had two colored variations released in the form of the Golden Monster Lord Axe and the DOOMED Monster Lord Axe.
- When the player goes to Dethrix's throne room in Ebonslate Fortress after Valen's futile first attempt to defeat him on his own, they can see several corpses of heroes that Dethrix felled when they challenged him, showing how powerful Dethrix proved to be.
- When Dethrix is defeated in an in-game battle (outside of cutscenes, that is), he explodes into a burst of Chaos magic. This is a reference to how some Chaos monsters explode in a similar fashion when they are defeated, and is even a reference to all of Chaos itself, alongside the fact that he gave Drakath the Chaos Eye amulet.
- Sepulchure killed Dethrix by ripping his heart out so he would make sure he could never threaten anyone again. Similarly, his son Drakath did the same to Sepulchure in the beginning of the 13 Lords of Chaos storyline; by ripping out his former master's heart of darkness and then crushing it in his hands.
- Originally, Dethrix was described as a DoomKnight and was fought at the bottom of the Necropolis, according to the Legend of Sepulchure storybook found in the Necropolis Dungeon. This was changed so that Dethrix is the same former king of Swordhaven that was overthrown by the trio of Alden, Lynaria, and Valen, and that he was fought in Ebonslate Fortress instead.