Cayde's memories of being a human who was converted into a machine by giving everything to the ice is reminiscent of the "machine people" who play an often very sinister role in Leiji Matsumoto's Captain Harlock/Galaxy Express 999/Cosmo Warrior Captain Zero sagas. In one version* (The first Galaxy Express 999 movie) the machine men are created with technology from the planet Heavy Melder and are rich people converted into all sorts of machines to be faster, stronger, smarter or immortal but they lose their humanity over time and many oppress fleshy people out of contempt, become obsessed with one thing, or become bored and dejected seeking meaning in a never ending life with no challenges or real hunger or want. They are humanity becoming inhuman and oppressing themselves which makes the poor and weak want to become machines themselves which the machine people hold over them. The machine people store their abandoned meat bodies on the ice world of Pluto. One of them, Claire, a waitress with a glass like machine body has fallen on hard times and waits on passengers on the galactic railway for money because wants to earn enough to buy her old body back to become human again. Maetel, a woman from the machine people is in a cloned human body because she wished to defy and annoy her mother, the queen of Heavy Melder. She visits a body in the ice that is presumable her original human body from the early days of the process when only the rich were allowed to become machines.
So it's possible that the gave everything to the ice line is a nod to ideas about trans-humanity from the first Galaxy Express 999 movies. Or not.
- (Each 'saga' follows a progressively revisionist format following certain thematic principles where one replaces the previous one instead of forming one coherent continuous narrative. One can think of it as multiple parallel universes but the intent is more to have the characters form a mythology or folklore such as that of Robin Hood or King Arthur rather than one objective history. Captain Harlock in one movie or mini series is a separate manifestation of the Harlock archetype rather than a character with one specific past or goal. If taken as sequential the stories will conflict on many points.)