Lien-Da is a echidna and has a complicate history.
Long story short she is power hungry and done a lot of horrible things in trying to bocem Grandmaster of the Dark Legion that always backfire on her.
She and her brother plot to kill they father to become co-grandmaster of the Dark Legion, to be fair the guy was a neglectful father and after they mother die become even mroe negleftul and almost imidialty marry another woman and process to give more attention to Julie-Su (her half-sister) more than them (not that was a high par to pass and Julie-Su still se the guy as distant the best of times). Once the deed was done Lien-Da was caught in the explosion of her own gun she use to assassinate her father and bed ridden, her brother explain that the explosion on purpose say he will become the only grandmaster of the Legion and make her the second in command. This will not eb the first time of course this backfire on her.
Somethings happen later, that she and some member of the Dark Legion come to Eggman in exchnage for cybernetics they will serve him she even try to use that opportunity to once again become grandmaster only to have that position rip off from her that apperently her grandfather, Dimitri, was speaking with Eggman and he convince the doctor to make him the grandmaster and put Lien-Da in second on command.
Later she betray her grandfather when the guy was trying to come up with ways to disable all the bombs in the Legion's cybernetics, not that the majority of the Legion is even aware of such fact, and declare her intent to be grandmaster.
She gets the position only to be blow up when she try to usurp the Eggman Empire, no she did not have a plan she simple saw a opportunity and try to take despite having no ways to ensure that. Eggman rebuilt her, keep her around because she find her ineffectual attempts to betray him fun.
Now as leader of the Dark Legion, Dark Egg Legion as Eggman's mocking name for it, proves she is not... all crack up to be as a leader as she thinks she is. In fact she pretty much incompetent, she is a good enforce but no leader.
So that's her whole story that skips some important details about her character.
Look a pretty bad character right?
However a possible future call Light Mobius, does show that she is actually capable of change. She is the grandmaster of the Dark Legion in the future, that was reduced to a social movement, manage to bury the hatch with her half sister, actually listen to the advice of her grandfather and is a loving mother, single too. In fact she change so much the protagonists actually keep her on the loop over things happening in the mini-arc.
Lien-Da will not scheme against Eggman, mostly because she is a more of a opportunist that will take the opportunity to grab power if present itself regardless if she has the means to keep it or not. So she can be handle more easily than Snively and well if you strip this character of all the power she has, she will be forced to give one long and hard look on herself.
But if they did, wouldn't they disable the bombs already?
They have no idea the bombs are even there and Lien-Da never see fit to inform them of such fact, mostly because it was her idea to go to Eggman and they would demand a new grandmaster in the spot.
