RTF is a global modification that replaces all towns in the game.

It seems to me that these girls are more like a modern version of Mormo.

I don't know those... I rarely delve into folklore-based undead; people fear the same things – ghouls, vampires, and spirits that cause nightmares and sleep paralysis. I don't remember anything surprising me there. And the main problem with folklore creatures is the lack of names for their upgrades. You could, of course, follow the principle of the third game and add the words "kings" or "royal" to the names, but that won't work for alternate upgrades. Here, the word "sisters" is a great idea, meaning there is some kind of "sisterhood" – perhaps it's a coven, or maybe it's the name of a combat group. In the second case, you can develop the story further: perhaps in ancient times, they were nuns, or maybe priestesses of a god of dreams, a god of the moon, or even a god of the sun and harvest? It's not that important; war changed everything – there are no more monasteries, no more empire, and the remaining Sorceresses hide in ruins and roam the swamps, hunting lost adventurers. Somewhere there, the Archons also hang out – ancient mages and priests who sold their souls to the god of death