Since reaching enlightenment, the Purple Pilgrim has never left the Purple Oasis. It's possble that he survives on scavenged Blue Darts—like other desert explorers—or even the magical plant life of the Oasis itself.
Followers of Nachi believe him to have divine significance, and that he simply sustains himself on the magical energy from channeling two opposing Spheres. As no-one else has ever achieved this feat, it's impossible to say for certain.
No-one knows exactly what happened, and the Pilgrim hasn't shared his story; the next time someone found their way to the Purple Oasis, they found him happily living there, having become a Sphere Bridge and gained the ability to channel two Spheres at once.Heresy (click to reveal)
Detractors of the faith claim that the Purple Pilgrim is no longer that monoduga at all, but a Shade or some other creature from one of the Spheres, hence his unwillingness to leave the Oasis.
An impossible cluster of alien plant life, the result of magic leaking into the world from one of the Spheres