So… what's the deal with Guardians and aging? I know they can be resurrected over and over. But do they get older? If you become a guardian as a teenager do you stay that way?

Are you asking if they'd be a horn-dog forever? j/k

I'd guess essentially ageless, excepting they may take on the personality of their original self and by extension it could be age specific.

I think much of their humanity gets erased when they are resurrected. Imagine living longer than anyone you ever knew or would know. What a horrible fate.

I believe their brains must get rewired so that success in saving humanity does not include pro-creation.

Pretty much. See: Efrideet.

A couple of other data points:

- Both Zavala and Saladin look the same age in cutscenes set some 500 years earlier.
- Early on Tyra notes that without the light she physically cannot make the journey to the Shard of the Traveler with you because she is feeling her age.

osiris aged, but that might be due to him not having access to sagira for so long.

Do Guardians have to eat? Sleep? Are they even human (or Awoken, I guess) anymore?

My Guardian has grown gaunt and wrinkled between games:

And his hairline is receding: