I can't replicate it.
Check if you're indeed using the version 21.1 of Essentials together with its hotfixes. That way I don't see why the 2.5.0 version wouldn't work.
Some stuff from UltimoSpriter (Deviantart) and some stuff I ripped from the games. Some of them aren't even tilesets, I just edited the map images from Bulbapedia and put the overworlds and shadows over them.
It seems like you might not have installed the other plugin properly or it doesn't support 100% mine.
You should check with the creators of the Z-Power plugin to see if that's supposed to happen. I'm not familiar with the code they used for recreating the mechanic.
With "disappear" you mean to have their opacities decreased? Because that was how I did the animation for the older versions.
Otherwise you may not have installed my plugin properly.
Old animation below:
Honestly, I never messed up with that part of Essentials, and I don't think I know enough about how the framerate works in v21.1, so I can't really help you, man.
You could change the Wait values in the Script though. Since you want it to be slower, just decrease them all proportionally until...
When I was doing loads of tests with my plugin and a clear Essentials, the clear Essentials returned that error with the bag too. And no, it doesn't happen only when messing up with the charms.
Maybe I'll give it another look in the future, but since it doesn't seem to mess up with the game and...