So in oblivion, you hear that the morrowind player went to akavir and hasn't come back. In Skyrim a certain Daedra makes reference to the fate of your oblivion character. In VI we might hear of what became of the dragonborn/TheChosenOneForEverythingDueToBadWriting.

But, I want to see what the community thinks those characters are doing/what are their traits. Because all of them were pretty limited due to gameplay reasons. What are they like in lore?

My thoughts on the matter:

The nerevarine mastered all the skills. All of them. So although a master of the blade (able to hit a mudcrab over 99.9% of the time) he also knows the widest array of spells due to mastering every school. But most importantly, he understands Chim. This, combined with the fact that everyone recognises him to an annoying degree, caused him to master the art of changing his race whenever he feels like it. The public thinking he's 'away in akavir', he really just wanders the world compulsively looting everything. When he does fight, He flies out of reach, becomes entirely undetectable and invulnerable. His armour is very indoril- like, and he wears wraithguards on BOTH hands, because CHIM

Champion of Cyrodil

Stuck in the madhouse, thinking he's some kind of Savior to sheogorath, when really he just went mad.

Dragonborn

Wears Dragon bones. Uses melee and shouts, because normal magic is very poor in skyrim. Got lost in a library, searching for a good writer, but never finding one.

(okay, that one was a bit [censored]y. but what do you think happened to the heroes after they stopped being played?)

I picture them vanishing from the historical record. I like to imagine them living out the rest of their lives in peaceful obscurity. They now have time for all those hobbies, like gardening and model railroading, that they didn't have time for when they were saving the world.

I don't believe the Nerevarine necessarily went to Akavir or that the Champion of Cyrodiil necessarily became a mad god. Tamriel is filled with rrumors and those might be two of them. I like to make up my own stories.

The devs usually make the issue so open and vague that the PC's ultimate fate is ultimately up to them. They might feel slightly obligated to give a vague refrence to appease those that feel like there needs to be a concrete answer to things, but they're so open and vague that it ultimately doesn't matter. Did the Nerevarine go to Akavir? Would you trust that on rumors from people who don't know anything about the Nerevarine in the first place? Is Sheo the CoC, or is it a completely different schmuck (Like my DB Listener, for instance) that happened to be around for Oblivion?

Simply put, its ultimately what you the player deign to do whatever you want to do with them. After all, they're your character. Beth knows the motto of their series (Be whoever, whatever you want), and allow us to do with them whatever we wish. That is a level of control that I love and adore about this series, and I wouldn't have it any other way.

Exactly, and for that reason, I don't have any single idea about our heroes' fate.

We could think of it this way... Each of us has our own little "parallel universe Tamriel," all a little different from one another, where events act themselves out endlessly, in many different ways. Our heroes inherit the "lore," but each one acts as an individual. And even if we were to come across a history book that told us exactly what the Nerevarine did and didn't do, that history book only applies to one of those parallel realities (the factory-standard one that Bethesda puts in the can), and not necessarily to any of the others.

So I don't worry about what Neloth says in Skyrim, about the Nerevarine being a "he," because one of my female Nerevarines killed him over 200 years ago.

What do they become?

Legends.