1) Poison Ivy
Poison Ivy was also on our list of characters we would love to see in a Harley Quinn spinoff movie, but on second thought, it might be more interesting to have the villainess first appear in a Suicide Squad sequel.
One thing that a follow-up needs to do to appease a large number of fans is to address the unhealthy quality of Harley’s relationship with the Joker. In the comics, this is usually done by having Harley escape the madman and enter into a much more loving friendship/romance with Poison Ivy.
The sequel could see Ivy joining the team and Harley realizing that she doesn’t have to be stuck in an abusive relationship. A Harley solo movie, then, could see the pair going at it alone, while the Joker is waiting in the wings to reclaim Harley.
Feel free to have this idea, Warner Bros., we just want a cut of the profits. 50% should do…