"Time Out of Mind" by John Byrne.
The Phantom Stranger doesn't actually appear in this issue, rather John Byrne took the time to draw in him when Wonder Woman recalls her back against Morgan Le Fay, which happened in Wonder Woman #'s 105-108:
Kind of a waste of purchase from a Phantom Stranger POV, but the story's a lot of fun, plus there's a great back-up drawn by Jill Thompson, and a killer pin-up by Brian Bolland.