Sketch of the outside profile of the sword body lofted to a single point some distance away. The longer the distance the more gradual the point will be.
Either create or copy the existing profile of the sword.
Create a plane parallel to the first sketch plane.
Create a sketch containing only a point where the swords tip will be.
Use 'loft' from the profile sketch to the single point.
Final with body, Fillets added for blending but not necessary.