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

I came up with a description for the sisters, maybe you'll like it. As they say, I need the author's approval.😅

The Sisters of Sorrow are an ancient sisterhood of Erishian necromancers who, during an unsuccessful experiment to turn them into vampires, became immortal spirits trapped in the armor of their order.

The Sisters of Terror are the highest necromancers who were on the verge of becoming vampires, but now they are unyielding spirits sowing terror in the hearts of their enemies.

(I replaced the names of the Wailing Banshees with Sisters of Grief, I saw it in your VK). The Sisters of Grief still cannot come to terms with the fact that they are now only the spirits of their former selves, and now their grief is conveyed in continuous wailing and screams.