So I like to add more variation in the enemies that my players can go up against so some of them are characters I've actually made and personalized for them to fight. Scrolling through every character I've ever made can be a hassle. I was wondering if there was a way, or might ever be a way, to sort them into categories or to allow dm's to create extra campaigns and add characters like these as well as other npc's that we've previously created to those campaigns as a way to sort them. Currently, the only option I see is recreating all of those characters as unassigned characters in my campaign. Obviously this is doable but very time consuming and, as my players are already pretty far into the campaign, there would be a lot of npc's to transfer over in that way.

Sorry if the wording on this is weird or confusing. I work graveyard shift so I'm almost always running on very little sleep.

Hello, when you add a character to a campaign using the join link, you can select any character you have made that is not already in a campaign. Hope that helps!

Even if I'm adding it to my own campaign for the purpose of organization?

Yes, you can add your characters to your own campaigns. :)