Adds a new sword to the game (no replacement). The Scarlet Vengeance can only be crafted, under the Daedric perk smithing menu. You are going to need an human heart and a couple ebony ingots in order to craft it.

If you are too lazy to go avenge someone and collect your victim's heart, type in the console "help Scarlet 0" and then use the player.additem command to cheat your way to get the sword.

Not much else to tell you about it. If you need some help installing, here it goes:
Copy the "data" folder provided in this package into your "C:Program FilesSteamsteamappscommonskyrim" or wherever is located your Skyrim installation folder.