I think they Halloween event could benefit from a location change.Thank you for the response the additional information that you provided really helped. I've watched the TAS since I was a kid and did not know green skin ivy was a clone. I thought she was just re designed because of the art style and it was explained her powers changed her appearance.
As for the other ideas in regards to different costumes I personally like most of the Halloween costumes (like queen bee and galateas costumes ) I was not a fan of jinxs Halloween costume though. (I think I just don't get the reference)
Overall I'm happy with the content provided. O just liked the ideas
Storywise, if Superman or, God help Luthor, Batman would scope out the yacht during that event and spot one of the captured girls, dressed up or not, the jig would up.
Have the party at Lexcorp, give it lead linned window shutters, a ballroom, guest rooms and a suite for Luthor for the finale scene.
You could even have a smalle scene at the beginning of Superman threatning Luthor and him mocking him with "just a smalle get-together for some friends."