You're the Ashen one of Lothric or the unkindled one anyways your job is to find the Lord's of cinders and have them sit on their thrones and you've gone through many areas felling tough foes getting some strong weapon and cool armor along your travels you constantly return to firelink shrine to enhance yourself and weapons you eventually meet a man named Patches a man you've met before after he caused you to fall into a pit of giants he asked for mercy and you showed it anyways he sells you a key that allows you into the locked tower outside of the shrine and you climb up and find a fire keepers soul and you head to the fire keeper and give it to her and she's surprised at first

Fire Keeper: Ashen One this looks like what i already have very well may it rest in my chest

After she says this her chest suddenly grows bigger