So I started a SMP with my friends a while ago and I really wanted to add the Origin plugin, but I found out it wasn't on the platform. I would surely love if it gets added. The mod supports 1.16.5 and adds some kind of superpowers to every player. For example if you choose Enderine, you get the powers of an enderman with a few drawbacks like: you take damage in water and you are afraid of pumpkins.
The plugin is really fun and a lot of people would love to have it added.
Link:http://www.9minecraft.net/origins-mod/ or https://www.curseforge.com/minecraft/mc-mods/origins