age is not a problem, even if you're not an elf, once you become Nerevarine you stop aging so you're good with that. As for the CoC and the shivering isles, just treat it as a bad trip from you brief escapade in the realm of madness... one you've finally recovered from as you awaken to be executed at the beginning of Skyrim heh.
This. This is one way of doing things. And I've thought about something along this line for post main quest mod...
But doing all the TES games... sure it's possible to mod that... but it would be a long, long time before such a mod would be done... Even if you had 20 or 30 full time modders and 20-30 texture/mesh/model peopl full time as well...
And then you'd have to consider the time jump... That can actually be explained away and still be within lore...
Arena - Start character, finish quest... not a big time jump to DF
Daggerfall - Character continues a little older, finishes everything, rides off into the sunset
Morrowind - Again not a big time jump here - Nevarine goes to Akavir at end of things... and is immortal from main quest line (convenient!)
Oblivion - iirc it's only about 6 years or so from the end of MW... so Neravine goes to Akavir, doesn't like the chile, comes back home... becomes CoC, Sheogorath plays "Let's mess with the CoC's head for a couple centuries... because it'll be fun and that's the kind of dude I am!"...
Skip 200-ish years...
Skyrim - Sheo "Just messing with ya dude, have a day!" Queue up "Gonne get yer head lopped off scene" (Hey backstory for folks now why you'd be crossing into skyrim!

) and off we go to save the world ... for the umpteenth time.
See? All within canon... a little shaky, but nothing actually contradictory to canon.
