We were having a discussion about Batgirl and I posted how i do do the plot with Killer Moth and then getting enhanced through some other means besides Neron.
But later I got to thinking. Would an Underworld Unleashed subplot work in the movies?
Aquaman - villain Black Manta. Manta sells his soul to become an actual ray like creature.
Batgirl - Killer Moth, sells his soul to become more powerful.
Nightwing - Block Buster, sells his soul to become smarter.
Shazam - is the person Neron wants to corrupt.
We could potentially find others.
Eventually leading to an Underworld Unleashed movie.