This is heavily AU, snippet-based, and definitely waaay too optimistic, but I like alien Guardians and hand cannons with explosive rounds.
This is tied with another massive fic of mine called Whispers of Darkness, and thus takes place in the same universe as it and Of Dragon Queens and Deathclaw Tamers. Not gonna crossover for ages, though, so feel free to just take this as a standalone fic.
It's usually the other way around.
Maybe not common, not in this so-called Second Golden Age, but every so often, a Guardian will lose their Ghost to the myriad forces of Darkness, in turn forever losing the ability to resurrect, and much of their ability to wield the Traveler's Light. It's a terrible phenomenon, a tremendous loss that no one but another Guardian can possibly relate to, though one that's fairly easy to avoid - Ghosts rarely phase back into three-dimensional space outside of safe spaces, like the Last City, and even if they do, it takes a weapon of ontological power and paracausal effects to truly kill one.
Naxos is very much alive. His Guardian, however, is dead.
Death is, of course, so intrinsic a part of a Guardian's experience that some even count it as part of their skill set, but then none of them have experienced Ariadne's fate - died her last death, swallowed by the fading soul of an incomprehensibly powerful Hive God she was one third responsible for slaying. No matter what Naxos tried, or how close he got to Oryx's titanic corpse, inching ever closer to Saturn's crushing depths, he was ultimately unable to bring her back.
It's quite the shock, then, when he feels that pull again. The undeniable magnetism of a chosen, a heroic soul meant to be raised from the dead in defense of life, freedom, and of course, the Traveller.
The corpse he finds at the epicenter of the pull - in a suspiciously sealed off section of the Arcology on Titan - is not human. Not Awoken, or Exo either. It's not ancient, either, like Ariadne's body was, brittle bones bleached by centuries of exposure in the desolate reaches of the russian Cosmodrome.
No, this Fallen - Eliksni now, regardless of the colors of Dusk he apparently wore in life - died recently. Naxos can only guess at the exact circumstances, but it's plain for anyone to see that he perished in battle with the Taken, like most of the life forms who die in Sol since the Hive Dreadnought arrived in-system. His upper right hand still clutches onto a Taken Hive sword - a rare sight, as most Taken weapons disintegrate along with their bearers upon defeat - and most of his body bears burns so intense that his armor and leathery hide have hideously fused in places. The hand that clutches onto the sword is corrupted, of course, the darkest black imaginable, pockmarked with white pinpricks of transdimensional light. It twitches, still, 'glitching' the way all Taken bodies do.
It's unorthodox, to be sure. But still, Naxos is as confident as he was when he found Ariadne. He brings him back.
His tiny form splits open, like a flower in bloom, petals spread to catch every iota of the Traveller's omnidirectional power, syphoning the paracausal current into the Captain's lifeless corpse. Light burns away his broken armor, washes away his myriad injuries, and seeps into the trillions upon trillions of molecules that make up his being. The energy bonds with his every atom, becoming intrinsically tied with the particles that make those up, in turn. The body, now alight with life, gives back in the form of memories, the sole price the process demands in return for eternal life. Only one of these stays with Naxos, and it's a name. Most Guardians don't even get that.
The Ghost can't smile, not corporeally, but his one blue eye does seem to glow brighter as the Eliksni draws breath for the first time in his remaining lives. "Hello, Misraks! I am Naxos, your Ghost, and you...you are a Guardian."