When Dr. Finitevus used Knuckles as the new Enerjak instead of either Lien-Da or the brainwashed Remington, both turned against him and used their Flame Legion and Frost Legion factions of the Dark Legion in an effort to subdue the chaos demigod. However, Enerjak's power proved far too much for the Legion's weaponry, and as part of his plan to restore Echidnas to their former glory, Enerjak used his Chaos powers to remove all cybernetic enhancements from all legionnaires, as well as restoring Remmington's lost memory. Enerjak went on to teleport all of the Echidnas to Albion, with the exception of Lien-Da and her few loyal followers, who were enraged at the loss of their cybernetic enhancements. After the devastating attack by Enerjak, Lien-Da sought out the help of Dr. Eggman to restore the Dark Legion's cybernetics as well as her level of authority and power. After allying with Eggman and submitting to his rule, Lien-Da found out that Dimitri had already been promised the role of Grandmaster over the rechristened "Dark Egg Legion".
Prior to any major post-Enerjak offensives against it, members of the Dark Egg Legion were seen patrolling the ruined city of New Megaopolis in Egg Mobiles when Mighty the Armadillo was sent there under the mind control of Mammoth Mogul. Even as Mogul's slave, Mighty proved to be too much for them when he was directed to return to New Mobotropolis and ripped his would-be captors' vehicles apart.
Not long afterwards, Knuckles led the Chaotix and Sonic the Hedgehog against the Dark Egg Legion in New Megaopolis. Holding himself responsible for their alliance with Eggman due to his actions as the new Enerjak, Knuckles hoped to convince their leader to change their mind and end their alliance with Eggman. By this point, the Dark Egg Legion was re-equipped with cybernetic enhancements and weapons, but still proved ineffective against the Chaotix and Sonic. Though Knuckles did his best to persuade Lien-Da to end their alliance with Eggman, she declined, still feeling resentment for Knuckles' actions as Enerjak and blaming him for their situation. Backup soon arrived in the form of Dimitri with a massive preying mantis-like robot body. Dimitri exchanged words with both Knuckles and Julie-Su, finally ordering the Dark Egg Legion to simply attack the Chaotix. Despite his help, the Dark Egg Legion was no match, and in the end of the battle, the communications relays station were successfully destroyed, and Lien-Da ordered the Legion to withdraw further into the inner city. Shortly afterwards it was explained by Dimitri he was deliberatly weakening the Eggman Empire from within by leading the Dark Egg Legion to constant defeat, which was why he allied with Dr. Eggman.
Following this, Dimitri confronted Eggman with regards to him having time to produce Metal Sonic and Metal Scourge while not supplimenting the Dark Egg Legion. During this conversation, Dr. Eggman revealed he had placed explosive devices within the Dark Egg Legion's cybernetics in order to prevent mutiny. Dimitri soon discovered Eggman was not bluffing when he examined Lien-Da.
After this, the Dark Egg Legion remained within the Eggdome as the rest of New Megaopolis lied in ruins. When Snively ordered Lien-Da and another Legionnaire to salute him, they simply laughed in his face as he was just as much a subordinate of Eggman as they were, much to Snively's indignation.
During the big push against the Eggman Empire by the Knothole Freedom Fighters and the Chaotix, the Dark Egg Legion under Lien-Da's command was first positioned in the outskirts of the ruins of New Megaopolis. They seemingly halted the advance of the Freedom Fighters until they were flanked by the Chaotix. Forced to retreat and regroup, they set up a defensive posture and refused to surrender. Before they could fire their weapons however they were deactivated by Tails' Neutralizing Mines. Dr. Eggman then arrived in his new Egg Phoenix and attacked the two Freedom Fighter groups, nearly killing the Legion in the process. After the Egg Phoenix was destroyed the Dark Egg Legion retreated back to the Eggdome where they were ordered to set up a series of defensive lines, as well as build a barricade with a hole just big enough to allow Sonic to get in while keeping the others trapped out, as part of Dr. Eggman's plan to face off against Sonic alone. Once the Freedom Fighters and Chaotix pushed into the Eggdome, the Dark Egg Legion was forced back but eventually managed to blunt their momentum. At this point however they were ordered to stand down, and pull back, as part of Snively's plan to allow the downfall of Dr. Eggman. After Eggman's defeat, the Dark Egg Legion welcomed their new benefactor, the Iron Queen, by supervising the landing of her dirigible.
Because the Dark Egg Legion's cybernetics had been equipped with explosive devices by Eggman to prevent mutiny, Dimitri came before the Iron Queen and requested that the bombs in the Dark Egg Legion be removed. The Iron Queen explained that the cybernetics Eggman provided were too complicated and that she could not remove the bombs, but as a compromise, she gave him a brief-case filled with micro-chips that would block the detonation signal once installed in the Dark Legionnaires. Dimitri took the chips, but he showed obvious signs that he didn't believe her.
Although their worries of the bombs exploding were apparently only partially put to rest, the Dark Egg Legion remained allied with the Iron Dominion. Lien-Da soon oversaw the counter-attack against Sonic and Monkey Khan, who were trying to infiltrate the city. After the Dark Egg Legion received a fair beating from Sonic and Monkey Khan, Lien-Da ordered them to fall back as support and let the Yagyu Ninja Clan take care of them. The two groups were soon joined by the Iron King, Espio the Chameleon, and Lightning Lynx, who defeated Sonic and Khan. The Iron King then forbade the Legion from attacking the fleeing heroes, wanting them to spread the tale of their defeat.
The Legion were soon faced with another problem as Dr. Eggman escaped using his Egg-Tortoise. Failing to stop him, they were left in charge of maintaining New Megaopolis while the Iron Queen set out in pursuit, though some legionnaires were dispatched with the Yagyu Clan to pursue and recapture Dr. Eggman. Despite locating the derranged scientist, the small Dark Egg Legion force along with the Yagyu Clan were beaten back along with the Iron King, Iron Queen and Snively and forced to retreat. During this time, Lien-Da learned from Dimitri he had modified a single one of the microchips provided by the Iron Queen to make the user immune to the queen's Magitek. Rather than allow Dimitri to modify all of the microchips, she disabled his cybernetics and installed the sole modified chip in herself, after which she hid Dimitri in a box. Following this she distributed the rest of the chips to the Dark Egg Legion, leaving her able to possibly control the army with her own thoughts. Claiming Dimitri had fled, Lien-Da was promoted to Grandmaster of the Dark Egg Legion.
Later, they initiated a successful invasion of New Mobotropolis alongside the Yagyu Clan. They were led by the Iron King into the defenseless city, thanks to the Iron Queen taking over NICOLE. Having successfully invaded the city, the Legion, along with the Yagyu, began rounding up and imprisoning as many citizens as they could find. Patrols of Legionnaires would continue chasing after resistance fighters like Amy Rose and Antoine D'Coolette until the intervention of Geoffrey St. John, allowing all of them to escape. The Legion also gathered in the New Mobotropolis Coliseum as spectators and participants in the Legionization of a number of captives including Rotor Walrus, but attempted to stop Amy, Antoine, and Geoffrey when they interrupted the event to free the prisoners. The arrival of Monkey Khan and a team he had taken to the Dragon Kingdom to break the ties between the Dominion and its Clans added to the confusion, and with the departure of the Yagyu the Legion found itself alone in supporting the Iron King and Queen. Seeing her two oppressors occupied with the Freedom Fighters, Lien-Da announced to the Legion that they would be taking control of the Eggman Empire. When the Iron Queen learned of this treachery, she attempted to dominate them using the chips, only for Lien-Da to reveal her deception. The Iron Queen promptly set off the bomb in Lien-Da's cybernetics, injuring her and freeing the other Legionnaires. With both Iron Dominion leaders occupied and Snively fleeing in terror, the Legion retreated for the Eggdome, taking Lien-Da with them.
After their return to the Eggdome they came under Eggman's control once again. With their Grandmaster's current state of health and in dire need of medical aid, they had no other choice than serving him in exchange for emergency cybernetics. Lien-Da was restored to health and retained the chip that would allow her to completely control her Legion, though Eggman had rendered it useless in blocking her newly installed explosives as well as those of her fellow Legionnaires. Regardless, the Legion set about renovating the EggDome, transforming it into the terrifying battle fortress known as the Death Egg Mark 2. Serving as crew and passengers, the Legion was caught up in the effects of Operation: Clean Sweep but were restored following Super Sonic's use of Chaos Control. They continued to serve as crew for the Death Egg throughout various operations, including attacks on Elias Acorn, Furville, and Feral Forest, as well as making forays to Eurish, the Dragon Kingdom, and Soumerca before another attack on New Mobotropolis. Eggman also announced that the Echidna Legion would be allowed to select its region of occupation as a reward for the sevice it had provided.
Typical Dark Legionnaire (Echidnas)