That boss is the opposite of fun. Friede by herself is mediocre. That giant joining in just makes everything easier. Once the game fakes you out and brings her back things get ridiculous. Not only is she moving all over the screen with area of attack weapon magic, but she also has an instant kill move. Do not know how soloing this boss without a summon is even bearable to most people.
I doubt anyone that plays Dark Souls 3 ever opts to start the other DLC before end game by going through this bullshit boss after a quick run to the Cathedral of the Deep.