I was there at the last 24 hour party. We waited for the villains characters. I hope they change it this year because last year it was really dumb. The villains weren't schedule to come out until around 2 or 230 am. No idea why they couldn't come out sooner. We had FP+ for the second electrical parade, right after that was finished we got in line for the Hercules characters, which we had figured would be the most popular as Meg and Hades were very rare. So we were in line a little before midnight. I believe the line was cut off around 1, with the people at the end not being guaranteed to meet anyone. So we spent a few hours waiting for them, then when they finally came out we realized Disney was doing that dumb character switch thing. Meg and Hades met for half an hour, then Pain and Panic came out. No offense to Pain and Panic, but no one really wanted to see them over Meg and Hades. Of course we were about 10 groups back when Pain and Panic came out. They forced 2 groups to go meet them and then get out of line. One girl was crying (no joke). Then after those two groups the rest of us banded together and refused. The poor CMs walked the line seeing if anyone wanted Pain and Panic, I think maybe 3 groups from the back of the line came up to see them. The rest of us held firm for Meg and Hades. After Meg and Hades came back, we noticed that there were now a bunch of Disney suits and about 5 security guards. We assumed that the next time that Pain and Panic came out people would be forced to meet them or else get out of line.
Have I mentioned that I hate it when Disney does stuff like that?
Anyway, we were done with our meet around 245. At that time, all the other villains had really manageable lines. Well, except for Maleficent and the Snow Queen. They were meeting at one side of the Princess Hall and I believe that line was as bad as the Hercules line and also got cut off.
But we basically walked up to Stroganoff, Bowler Hat guy, Facilier and several others.
Also, I think our plan for last year's 24 hour event was pretty inspired (if I do say so myself). We were there at opening and were able to walk onto stuff (including an early opening of 7 dwarves). We had lunch at Cosmic Ray's around 11 and then the park started to get pretty crowded. It was also getting hot, so we went into our midday strat, which was to do things like COP, Tiki Room, HOP, TTA and so on. So lots of air conditioned breaks and sitting. We had a dinner ADR at 7 for Crystal Palace for more relaxing. Then we had a BTR FP, an Anna and Elsa FP, and a FP for the second electrical parade. After that we got in line for Hercules characters, and by the time we were done the park was pretty empty and we ran around getting more villains and riding things with no wait.
It sounds like we missed most of the bad crush of people because we were eating, using FPs, and then waiting for Hercules characters.
I also have a detailed trip report of that day in my signature, under the 'star wars weekends and 24 hour MK day' report.