It is the universe owned by Shahzeb .
It is a very complex universe. There many iter-dimensional reams, data/fake dimensions. Different flow of time in a dimension makes alternate timelnes. A complete reboot in a timeline or a timeline where life is lived so differently is called an alternate dimension.
It is the dimension of Archaic Shahzeb. The humans of this dimension are Skeletal-ish to their cannon counterparts and have firebending abilties. It is also inhabited by Dino monsunos and is based on Fire Nation fro Avatar: The Last Airbender.
- Some characters like Paradox, Maltruant and some other beings do not have alternate versions.