Talos is the god of man.
To understand Talos is a complicated thing, and not easily explained all in one go.
Lorkhan is the god who tricked or convinced the other Aedra into making the Mundus, thereby sacrificing (parts of) themselves into the project.
The other Aedra decided to punish Lorkhan for this and ripped out his heart. Where it landed a volcano grew and this is Morrowind's Red Mountain.
His body was torn asunder and orbits Nirn as the moons.
"But when Trinimac and Auriel tried to destroy the Heart of Lorkhan it laughed at them. It said, "This Heart is the heart of the world, for one was made to satisfy the other."Lorkhan may have been dead, but even dead gods can dream.
Over the course of history many avatars of Lorkhan, or Shezarrines, have walked Tamriel. They fought on many sides, some even against each other and mostly all are remembered as great heroes.
During the time of TIber Septim several of these avatars all joined together to form Talos, the mirror-brother of Lorkhan.
The story of their collective feats, their fates, so closely matched the story of creation, up to and including the betrayal, that in the mythic sense there is no difference.
This act of mythical affirmation of creation merged the souls of these Shezarrines, Tiber, Hjalti, Wulfharth and probably a few others, into the mirror-image of Lorkhan.
This building of a new Lorkhan from the ground up instead of from above, as it were, is a big giant cosmic YES.
It strengthens the Wheel of Creation, and is therefore a thorn in the side of the Thalmor.
What appears to be an Altmeri commentary on Talos:To kill Man is to reach Heaven, from where we came before the Doom Drum's iniquity. When we accomplish this, we can escape the mockery and long shame of the Material Prison.
To achieve this goal, we must:
1) Erase the Upstart Talos from the mythic. His presence fortifies the Wheel of the Convention, and binds our souls to this plane.
2) Remove Man not just from the world, but from the Pattern of Possibility, so that the very idea of them can be forgotten and thereby never again repeated.
3) With Talos and the Sons of Talos removed, the Dragon will become ours to unbind. The world of mortals will be over. The Dragon will uncoil his hold on the stagnancy of linear time and move as Free Serpent again, moving through the Aether without measure or burden, spilling time along the innumerable roads we once travelled. And with that we will regain the mantle of the imperishable spirit.Its complicated but I hope this helps

http://www.imperial-library.info/content/monomyth
http://www.imperial-library.info/content/arcturian-heresy
http://www.imperial-library.info/content/walking-ways
http://www.imperial-library.info/content/five-songs-king-wulfharth-0