I don't think there's enough here for me to intelligently solve your plot issues directly, other than some general advice.
You're not yet in comic production, right? My first advice is to reduce the number of main characters you have, and see where else you can concentrate your story.
Then, if you have a desired ending, you can plot from where you are to where you want to go for each character. What single event would it take for Character A to get to their end state? Once you've found out what it would take for each character, think of a way to get those events to happen simultaneously, especially if you can get it into the same place and time. That's your climax, and then it's just logistics getting there and some bardic instincts to tell it in the most interesting way.