Szass Tam's Planar Essence

You have wrested away part of Szass Tam's essence, a fraction of his ability to travel the planes.  Choose one of the Outer Planes listed in Appendix C of the Player's Handbook; the choice is permanent once made.  You can use your action to cast plane shift on you (and only you) and travel to the chosen plane or from that plane to the Prime Material Plane.