Hello!!
I've been in a couple bigger servers before, some having a bit called Pluralkit. This bot is for people with DID/OSDD to help let their alters express themselves. (Please note that I personally and many people do not directly support the makers of this bot, but it is very useful nonetheless)
I know it may seem difficult to moderate, but you can see the base account and the profile information by reacting to any message sent with the bot with ❓. And you could probably just only allow it in general to make it even easier to moderate.
I know there's not a whole lot of other systems here, but Pokemon is something that really brings (especially neurodivergent) people together. And I think it would be cool to have!

