The elementium grinder creates the resource Elementium, which is already in-game as a very rare find from adventure locations. It can be used to design units with "legendary" gear. The Grinder costs 250 gildar and 25 materials to build, upkeep of 7 gildar per turn and reduces the prestige of the city by 1. It creates 1 elementium every 4 turns.
The resource and the armor was already in-game, I just added another way to find and produce the resource. It is also featured in the Elementium Churners mod, which also works with the Elementium resource.
I'll add what I can, it is not just about creating something but creating as much as possible with the least effort. For example, for the Living Stone and the Golem King factions, I didn't do any 3d modelling, I just used something that was already in-game in a different way and it worked out really well. The Drota/Goblins needed a bit more tuning, but again, I'd say 99% was already completed and I just did the last 1%.
I don't have any plans for dwarves, halflings, gnools or anything like that. The next planned faction is the Death Legion, consisting of twisted demons.