Which is it?
Anyways, as always they can make any villain cool with the right actor and writing. I think a properly done Captain Boomerang would be great, just the character himself would be a lot of fun. And they don't need to call him that except as a joke at some point, like they were joking around coming up with a name for Multiplex this last episode.
Speaking of, he didn't die on screen. He'll be back. The character is slated to be in the Suicide Squad movie, but these shows aren't part of the DC cinematic universe.