Warning: Contains SPOILERS for The Suicide Squad.
Harley Quinn is a key part of Harley (Margot Robbie) is one of the few characters to return from the original 2016 movie for James Gunn’s not-a-sequel, not-a-reboot. However, she’s been through a few changes since that movie released. Birds of Prey (And the Fabulous Emancipation of One Harley Quinn) introduced a new take on Harley Quinn; many of the core facets were still there, but there was no room for the Joker, with Harley revealing they’d broken up. With a fresh perspective on life and an updated wardrobe to boot, it seemed like Harley’s future was wide open. Unfortunately for her, the open road simply led her back to Belle Reve.
Yet again among of the team of colorful characters in The Suicide Squad, which is once more brought together by Amanda Waller (Viola Davis), Harley begins the movie on Task Force X alongside her old colleague Captain Boomerang (Jai Courtney), Savant (Michael Rooker), Blackguard (Pete Davidson), TDK (Nathan Fillion), and Weasel (Sean Gunn). Led by Rick Flag (Joel Kinnaman), it’s clear this isn’t exactly the cream of Belle Reve's crop. Sold out by Blackguard, all of the team bar Flag and Harley are quickly killed off, many in ridiculous and/or brutal fashion.
Harley herself is very skilled, so why was she relegated to the B team, rather than being with Bloodsport’s (Idris Elba) from the beginning? One possibility lies with Waller herself. As The Suicide Squad makes clear, Waller is incredibly ruthless and willing to do whatever necessary. She’s had a lot of issues with Harley Quinn, dating back to the first movie (and likely before), and her various escapes since then. Using Harley on the "bad" Task Force X team, then, could be Waller's way of getting rid of her for good. Still, she is nothing if not shrewd, and likely knew including Harley had other advantages. Without her, then Flag might’ve had more questions about the make-up of the team; putting someone with her skills on there ensures it works better as a diversion and gives that team a greater chance of success.
Given the loyalty he shows to her, it’s also possible Flag personally requested she be on his team. If it works out, then the mission can succeed; if it doesn’t , it’s no loss to Waller. Putting Harley on this team is basically a win-win for her. Another possible reason is that Bloodsport didn’t want Harley on his team. The Suicide Squad shows his Task Force X being assembled, and he sees (and is exasperated by) misfit characters such as Weasel, so it’s plausible he’d have rejected Harley too. There’s a sense that Harley ends up doing whatever she wants, so she may well have ended up on Flag’s team regardless, since she’s shown such a willingness to get out of Belle Reve any way she can on multiple occasions now.
Including Harley on the bad Task Force X also increased the stakes of the opening mission. With no disrespect to Boomerang, that team is largely a bunch of nobodies without Harley along for the ride. By including her, it makes the double-cross from Blackguard and the fact all of the other are so quickly killed off all the more surprising, because of the expectation that Harley will be ok. She is, of course, but the movie sets up her team lasting longer than it does precisely because she’s on it. Harley proves her worth to Bloodsort’s team and then some later in The Suicide Squad's story, but she’s key to that opening mission, even if she’s on the bad team.
