She brought Task Force X back from the (mostly) dead by sheer force of will, to accomplish what she wanted to get done.
Amanda also recruited a few specific people, Nightshade and Nemesis, that would help the covert nature of the team, and were heroes, which would also help deal with the criminal element that was a part of the team.
Here's the facts on these three Suicide Squad members.
Amanda found interesting people with problems to contribute to her cause....and Nightshade was one of the earliest.....
King Faraday, though most of the rest of her history was intact. Nightshade still wanted to get ready to go back to the Nightshade dimension, and did during the run of the Suicide Squad....much to her own and the Enchantress' dismay....as Eve took additional power from the Enchantress (and changed her costume as well). Eve did continue on with the Squad until its end, later joining up with a couple of other groups (and she even met Captain Atom as well, early on.....). But, she also fell for the man who helped her infiltrate the Jihad during Suicide Squad #1 (May, 1987).
Multiplex and Plastique, and many others like Penguin, Chronos, the Thinker, Captain Cold, Count Vertigo, Dr. Light, Poison Ivy, and heroes as well, like Black Orchid, Speedy, Shade the Changing Man, Manhunter, Katana and Vixen, and so many more, all a part of the team, and all there to do as Amanda Waller wanted....or else!
In the end, fighting for everyone, and laying down your life for others, might have been the best end people like this could have hoped for.