10 F*ck Ups That Made Suicide Squad A Disaster
9. Choosing The Wrong Source Comic
It might not have been the worst thing to use a lesser known comic as the source in order to concentrate on building the Squad first, but the Nightshade story simply wasn't the right choice. The villain wasn't notable enough, the story was too weird and really, it didn't warrant the interference of the Suicide Squad.
The Squad needs a reason to exist, and seeking a major threat as well as using the strong foundation of one of the more seminal comics would have been an easy win.
What Should Have Happened
Generally speaking, a classic Ostrander comic would have been the way to go: something like The Coils Of The LOA (or at least the start of a similar story). The best source to use would probably have been a collection of them: taking Mad Love as a more serious base to establish Harley Quinn and then using Coils Of The LOA as the narrative thrust.
Having the League Of Assassins introduced again would have been an easy way to tie to Batman, and it would have established credible ongoing threat rather than the need to bring in episodic monsters of the week for any sequels.