RealismEngine is a game engine made by Hattozo. It is a mix of scripts combined to make a realistic engine. If you don't like something in this engine, don't worry! You can edit the source code and republish it to make your own version. The only issue is that you're not going to get any updates from the module.
You can take the source code here: https://www.roblox.com/library/3095839264/RealismEngine-Loader