It's hard to get a sense of Emet's 'natural' lifespan given that he heavily utilized soul transference himself, albeit in a more restrained manner. Varis even kills Emet on-screen, forcing him to hop to a new clone body. It's also interesting that in 'Through His Eyes,' Emet chooses to maintain a distinction in referring to Varis as 'this body's grandson'. We don't have a sense of how long his original body actually lasted.

There's also the question of why someone would look into soul transference at all in a society like Amaurot. I'm sure that hijacking a fellow Ancient's body would be frowned on, and the Convocation doesn't tolerate acts of malice or deception. That's why I think that Pandaemonium might be the key to this puzzle. Eric's reactions suggest that the timing of Athena's return to the star wasn't entirely planned (we should have brought some Elpis blooms to that scene - Hermes would be thrilled to find a friend). It's also interesting that he accuses his father of being cold and not sparing any time to mourn, which seems completely at odds with Hyth's claims that returning to the star is always beautiful and something to be celebrated. Likewise, while we don't yet know what kind of a relationship Lahabrea and Athena shared, it seems interesting that the subsequent energy of that brilliant scientist was directed towards finding ways to ducktape souls to Creation magic. I really don't think this bodes well for either Athena or the family dog.