Are the files in the same folder as Game.exe? If not, Here is a Zip file containing the DLLs. Directly from Essentials v19.1. https://ufile.io/5tmjcl48 Paste the DLLs to the Game folder. If doesn't work on the files are already there, maybe you stored the game in a folder that requires Admin...
Just paste the whole zip in your project, or copy contents from The zip's graphics folder to your gane graphics folder, Audio in Audio and Plugins in Plugins.
Looks like you only extracted the Plugins Folder, you have to extract all the folders in your project root (the game main folder where Graphics Data Plugins Game.rxproj Game.exe.... Etc is located) to make sure all the files are there.
This plugin adds a better Mega Evolution animation to the Essentials.
How to use:
1. Download and Extract the Zip file to Project root.
2. Recompile Plugins.
3. Enjoy.