It's difficult to say We know the Golden age was at least two hundred years long, and according to failsafe the collapse happened 500 years ago. Meaning that's already 700 years If we're to believe that the Eliksni had the traveler literally right before us, then the whirlwind had to have happened at least 800 years ago or less We know that the traveler tripled human life expectancy, so it's highly possible it did the same with the Eliksni. Since we don't know how long Eliksni lived to begin with it's hard to say if being alive since the whirlwind is impressive or just a common thing. It's also possible that ether has rejuvenating properties, preventing Eliksni from suffering from old age unlike humans but that's just a theory