Chaos Lord is a Digimon that appears only in the video game Digimon World 2. He looks like Machinedramon, the only differences being his colors, his head, his cannons and his tail. He also resembles Chaosdramon, although they are not actually the same Digimon as many people believe. In Digimon world 2, Chaos Lord's species is referred to as ChaosLord; there would be no reason to not name him Chaosdramon if he really was one. The fact that Chaos Lord's species is "ChaosLord" reveals that he is not a Chaosdramon, even if he does have some things in common with him.
In Digimon World 2, Chaos Lord was the first Digimon that became wild. Angemon of the Meditation Dome says that, according to the legend, Chaos Lord became wild because he came into contact with a Grand Being. Then he began attacking other Digimon, and the battling spread over the whole File Island like wild fire. Chaos Lord earned his name because of that, and also became the Prince of Evil. In addition to that, Chaos Lord was the one responsible for the people of File Island to flee from it using the Archive Ship, since they had to do so after losing to him.
Akira, the main character in Digimon World 2, can not find where Chaos Lord is in the beginning. In order to do so, he must first defeat three Digimon with incredible super powers (as Jijimon of File Island says), who work under ChaosLord, and are known as the Chaos Generals. The Chaos Generals are the most powerful Wild Digimon after Chaos Lord, and each of them possesses a special item called the Chaos Ring. When the three Chaos Generals' Chaos Rings are combined, they can reveal the location of Soft Domain, where Chaos Lord is located. Akira fights and defeats the three Chaos Generals, collecting their Chaos Rings after each battle. When Akira gets all three Chaos Rings, he shows them to Jijimon, who then uses them to show Akira where the Soft Domain is.
Akira then has to go to Soft Domain and make his way to the 16th floor. There, he finds Crimson, the Blood Knights' leader, and defeats him. Crimson then leaves, informing Akira that Chaos Lord is waiting for him. Akira then has to make his way to Chaos Lord, but on his way there are some dangerous obstacles - red floor tiles (acid swamps) which can cause some damage to Akira's Digi-beetle, rendering it useless. At this point of the game, Akira does not have access to the necessary equipment to overcome those obstacles without having his Digi-beetle take damage. Therefore, he must use repairing items to fix his Digi-beetle when it takes too much damage. If he does not have such items, Akira's Digi-beetle will most likely not be able to continue any further, and Akira will have to leave Soft Domain before even having reached Chaos Lord.
When Akira overcomes the obstacles at the 16th floor of Soft Domain, he will then walk through five corridors of all Specialties (Darkness, Machine, Nature, Water, Fire), and in the end, in a large room whose floor is of no Specialty, he will find the Prince of Evil, Chaos Lord. Chaos Lord believes that he is the most powerful Digimon, and he reveals to Akira that he is planning to eliminate everyone except for himself in order to reach the peak of evolution. He states that he was even going to destroy the three Chaos Generals.
After being defeated, Chaos Lord tells Akira that he and the Chaos Generals will be revived into new forms by an item he gave to Crimson. Although Crimson himself never mentions it, it is assumed that his NeoCrimson form is a combination of himself, the Chaos Generals, but also Chaos Lord too, since he has his unique cannons and his feet.
In the end, it is revealed that Chaos Lord was a part of Overlord GAIA's evolutionary program, which would have destroyed everything had it not been stopped by Akira.
Interestingly enough, ChaosLord has 747 HP, even higher that that of Overlord GAIA, the final boss of the game. He is the character with the third highest HP in the game, surpassed only by the Guardians (who have 897 HP) and NeoCrimson (who has 825 HP).
Signature Attack
Chaos Cannon: Fires 1-3 shots from his cannons on the same turn.
Conversation
Before battle:
Chaos Lord: So you are Guard Tamer Akira?
Akira: That's right! I'm Akira!! Chaos Lord! I have defeated all of your men! You're next!!
Chaos Lord: You defeated all my men? Ha, ha, ha. So what? I was going to destroy all of them including the 3 Chaos Generals anyway! Only the most powerful Digimon can exist in this world! And that's me, Chaos Lord!!
Akira: What!?
Chaos Lord: All living beings strive to reach the peak of evolution! Only the winner of all battles will reach that peak. Which will be me! Do you really think you can defeat me, Chaos Lord, the most powerful Digimon?
After battle:
Chaos Lord: I congratulate you... for defeating me... I guess the most powerful Digimon on this island was just another Digimon in the bush... It seems that humans and Digimon training hard together makes for greater Digivolution. But I'm not going down this easily... Neither are the three Chaos Generals... We'll be revived into new Forms with the Item I gave to Crimson... ...That's it... That is what our Guardians desire...
(Chaos Lord teleports)
Akira: Chaos Lord... ............
In Digimon World 2, the Chaos Generals are three powerful Mega-level Digimon working under Chaos Lord, and presumably the most powerful Wild Digimon after him. Each Chaos General has a Chaos Ring, a valuable item which, when combined with the two other Chaos Rings, can reveal the location of Soft Domain, where Chaos Lord is. Akira has to defeat all three Chaos Generals when they come out of their hideout in order to find Chaos Lord.
After their defeats, and after Chaos Lord's defeat, the Chaos Generals and Chaos Lord are combined with the Blood Knights' leader, Crimson, and form a super organism known as NeoCrimson.
The three Chaos Generals are ChaosBlackWarGreymon, ChaosMetalSeadramon, and ChaosPiedmon.
ChaosBlackWarGreymon
ChaosBlackWarGreymon (C-WarGreymon) is at the 15th floor of Patch Domain. Akira has to battle him on a Fire Specialty floor. ChaosBlackWarGreymon battles together with a Triceramon and a Scorpiomon.
Signature Attack
GAIA Force: Shapes a massive sphere of energy and hurls it at his opponent.
Conversation
ChaosGreymon: Woooow!! Who the heck are you? This Patch Domain belongs to me the great Chaos General, Chaos BlackWarGreymon!!
Akira: I'm Akira! A Guard Tamer!
ChaosGreymon: A Guard Tamer? Ha, ha, you're so puny! Interesting... so you're the one causing problems for Crimson!! Then I'll destroy you and bring you to Crimson! Say your prayer, cuz I'm the slayer!
ChaosMetalSeadramon
ChaosMetalSeadramon (C-Seadramon) is at the 15th floor of Mega Domain. Akira has to battle him on a Water Specialty floor. ChaosMetalSeadramon battles together with a Megadramon and a Gigadramon.
Signature Attack
Ultimate Stream: Releases a devastating energy beam from his nose-cannon, striking all opponents.
Conversation
ChaosSeadramon: I have been waiting for you, Guard Tamer.
Akira: What!? How did you know that I was here?
ChaosSeadramon: I know everything! Is he having trouble dealing with a kid like you? He's not as tough as I thought. At this point, I should let Crimson beat you, but I guess I'll take care of you, myself. I, the toughest Chaos General, the great Chaos MetalSeadramon, will take you to school!
ChaosPiedmon
ChaosPiedmon (C-Pierrotmon) is at the 15th floor of Data Domain. Akira has to battle him on a Nature Specialty floor. ChaosPiedmon battles together with a Giromon and an Andromon.
Signature Attack
Trump Sword: Throws his four swords at an opponent.
Conversation
ChaosPiedmon: What? Who are you? Your not a weakling Blood Knight, are you? You must be the Guard Tamer after them!
Akira: That's right!! I'm Akira, a Guard Tamer!!
ChaosPiedmon: Ha, ha, ha!! You're a feisty little kid!! But soon you'll regret ever meeting me, the great General, Chaos Piedmon!! It'll be amusing to destroy you here and prove the incompetence of Crimson!