So we know for a fact Shoken was a contemporary to Laghima (who I will remind you lived 4000 years prior to Korra's time), at one point in "The Rise of Kyoshi" Lao Ge states in response to Kyoshi asking him if he is Shoken "Of course not. I was always much better looking than that fool.".

This would seem to imply Lao Ge is at least ~3500 years old. What do people think? I really like the idea that he is actually that old.

I've also been thinking about this. It's really cool and definitely possible, but I think he is more likely a few hundred years old since "I was always much better looking than that fool" could be interpreted as Lao Ge living at the same time Shoken did, but also as him looking better at any point in his life before achieving immortality than Shoken did during his own.

@Gligo13 Wouldn't that require Shoken to have lived an exceptionally long time? Of course that's not out of the question, indeed maybe that's where Lao Ge learned his ability. But I was not aware of Shoken having lived so long (granted I'm only now approaching the ending of 'The Rise of Kyoshi').