The Nirn "Arena"
Nirn is the Arena, a play-board. Let's say Aka gains his self-identity when he realizes that he himself exists and is, and here Time begins; and at the same time through the limitations that identifies the boundary of his existence against 'is not' splits out Lorkhan, which is Space, and for this this very spirit goes mad with internal conflicts. This conflict reflects into the Mundus Aka/Lorkhan and other et'Ada created, so the first meaning of the "Arena" is that Nirn is the chess-board of Aka/Lorkhan, with each kalpa a separate game yet the player always the same, and much of the conflicts on it mirror the conflict of Aka and Lorkhan, who fight to take control of the very existence. After the Rebel Lorkhan succeeds winning the game, the so-called 'Alduin' aspect of Aka 'devours' the world and Lorkhan takes the very heart of Aka out of him, in that Lorkhan becomes Aka and Aka becomes Loekhan, and through these the new kalpa begins with the players ready to act again. In different kalpas different creatures and cultures mirror their conflicts as that of Aka/Lorkhan, so these two-spirit-as-one exists in every culture.
Many Aedra die or merge into Mundus during this kalpa-exchanging process, yet the remaining 'Dead' Aedras do leave the world, because as Aka erects the Ur Tower declaring the game Time beginning and the heart of Lorkhan into Mundus steadies the world, there's no need for them to stay to keep the world stable. However what the mortals take as Gods are in fact their, especially Aka/Lorkhan's different aspects, many of whom ascend heaven by violence, mantling the Spirits or by magic or any other existing means, and others created through this process when Dragon Break occurs and so on.
And then are the Daedra, whose sphere are, one can say, indepent to Nirn as these are concepts 'not nature', 'not so-stasis and full of change', or I call it 'go to extreme so cannot be nature-balanced or calmed as those Aedra'. By force some Daedra are 'created' or transformed into, as Malacath-who-is-Trinimac and Dagon-who-is-Magnus, as their natrual balanced aspects are torn away from them so the remains are without any aspects root in Nirn. By born or by this process they become Daedra, who are NOT on the chess-board of Aka/Lorkhan, by contrast they are truly outsiders and are curious about the game on-show, and many of them are happy to involve into the game, which, by nature of course, is an unwelcoming interference of the origin game. Though Aedra managed to keep them out, when condition is right Daedra can still disturb the game. So here is the second Arena meaning, as the arena between Aedra/nature world and Daedra/pure pure outside concepts.
The game-board is the dream of Aka/Lorkhan and the World itself, as all is the so-called god is everything is I. So if a mortal realize this, and he decides to wake up, he just leaves the game forever and this is called a zero-sum. Yet if he keeps himself identity as his own at the same time and decide to stay on, this is called CHIM and he becomes a god of his own and the same time all god as him as all the world,aspect or not
That is to say, in the current kalpa, the mortal mainly mers and men conflicted as the different aspects of Aka/Lorkhan semi-self-conflicted, as the great ones of them mantled or transformed or merged into the concept of the dual-god. Before the Ayleid erected the White-Gold, the confict is normal and brings regular wars. But after that, a wheel in the wheel was established and it meant the total domination 'cause it was the hub of hub, and in my opinion the Wheel thing has its Daedric aspects. By this the Ayleid enslaved men and the Daedric aspects affected the Aedra natrual game plan, so we saw Allessia rebelled and became the queen, an armstice and transformation between Aka/Lorkhan against the outsider Daedra, and through Reman to Tiber Septim's Empire---until Martin destroyed the White-Gold Stone and Tower and Wheel, so things went back to the time before Ayleid when men and mer directly conflicted as a whole again, and that is the current situation on Tamriel.
Wonder if it's all right. Please correct me if I am wrong. Thank you!