You went inside the Haligtree only to find a girl sleeping on a chair, she then wakes up and attaches her prosthetic arm to her right side which has a katana connected to it.

Malenia: ...Heed my Words. I am Malenia. Blade of Miquella.

Malenia then swings her weapon slow but smoothly and the air to the right side.

Malenia: And I have never Known Defeat.