I re-read your post with a little more understanding once I’d seen the discord.

Multiverse is apparently a mod.

https://rpgcodex.net/forums/threads/arcanum-multiverse-edition.114150/

https://steamcommunity.com/sharedfiles/filedetails/?id=760410053

That link apparently expired or something, but I tracked down another that seems to work.

https://discord.gg/KT7sRzY

My guess is you’re looking for this:

http://terra-arcanum.com/drog/uap.html

Or possibly this:

https://www.nexusmods.com/arcanumofsteamworksandmagickobscura/mods/4

What’s the discord address?

I never beat it, but tlI enjoyed what I did play of it enough that if I could find my copy I might give it another go.