Krellenos was visited by Xing and Xang who convinced him to join forces with Drakath as his ninth Lord of Chaos. Krellenos was willing to sacrifice everything - even family - to gain Chaos power. He was followed by an army of Chaotic Chinchilizards, Chaotic Horcboars, Chaotic Koalions, Chaotic Lemurphants, Chaotic Rhisons, Chaos Tigriffs, Chaotic Vultures, Chaorrupted Good Soldiers, Chaorrupted Evil Soldiers, Chaorrupted Good Lieutenants, Chaorrupted Evil Lieutenants, Chaos Horc Spirits and Chaos Troll Spirits.
Krellenos chaorrupted his younger brother Antiphuus and sicced it on the players. After they defeated him, Druuz brought Antiphuus to the other Trolls and they recognized him. Not pleased with the players for what happened with one of their own, the Trolls still blamed the Horcs for the Chaorruption. Meanwhile, Krellenos went and stole the Accord of the Dark Sun to present to Drakath. Later, not long after the chaorrupted alliance was defeated by the players, the Horcs, and the Trolls, it was soon discovered that Bachius, Dregas, Sput, and Tlax had become Chaorrupted and were fighting each other only to be silenced by Sokrakiis and Kagg. Indeed, Krellenos turned out to be the one responsible for the chaorruption. As he teleported away, Kagg and Sokrakiis decided to summon the players.
The players, Sokrakiis and Kagg found Krellenos attacking a Serpentress and Chaorrupting the heart of the Ancient Temple. Khasaanda appeared, distraught by everything her brother had done. After she left, the players, Kagg, and Sokrakiis left as well as Krellenos bombarded the heart itself with a fireball. The Horcs, Trolls, and players then decided to gather everyone and go after Krellenos himself. Later, they indeed found Krellenos at the Ore Cavern, and alas, there he was, now as a full-fledged Chaos Lord, who held captive Cynari and Tibias (both of who were captured by the Chaos Twins earlier), and he used the power of the un-chaorrupted Arashtite ore to turn the Serpentress he kidnapped from the Ancient Temple into the Gruaige Baas. After the Bass' defeat, Khasaanda (sick of being made fun of by the other Trolls) stole his Chaos powers and absorbed them to usurp his position and replace him as the ninth Lord of Chaos. Khasaanda then had one of the chaorrupted alliance soldiers kill Krellenos before leaving to have a conversation with Drakath.
- After completing the Ancient Temple quests, he is replaced by a Fallen Censor.
- He is also the fourth Chaos Lord to act like a monster, the first being Vath, the second being Ledgermayne, and the third being Tibicenas. He Chaorrupted his own brother Antiphuus, whom the players knew they had to kill while hoping that Sokrakiis would understand about it. He also stole the Accord of the Dark Sun, and later began chaorrupting Horcs and Trolls alike, forcing Kagg and Sokrakiis themselves into a meeting, and laughed about it. He later went on to attempt Chaorrupting the Arashite Ore of the ancient temple, using a Serpentress to do so which transformed the Serpentress into the Gruaige Baas. Kagg later blamed Krellenos for Antiphuus' death.