The following plugins will help you get more from your the Default Side View Battle System the come with RPGMV and make it more unique with the specific setting you may want to have. Note: I'm not actively using all of the battle systems, therefore It's possible there are more plugins I didn't add here, let me know if I missed anything and I will add it as soon as I can. Please let me know if that helps you, the more people this resources help the more I want to create more lists like that (It still took some time to find them, test them and write this post and I know dev can look forever for the battle system they need).
Please note I'm doing this in order to save you time looking around for each of the systems below, you will still need to check for yourself what works the best for you, I hope this will be a short cut of finding your desire battle system. After taking some time to continue working on my own game I'm back with a list of all the 'Battle System' developers can use for their games.