In the beginning... 

The Creator created the [Wheel of Time], which is time itself. The Creator imprisoned the [Dark One|ShaiTan] outside of the [Pattern|Wheel of Time] at the moment of creation. A bore was made into the [Dark One|ShaiTan]'s prison, but it was sealed before he entered the world. It is now held closed by seven [seals].

Pretty vague, eh? Jordan seems to want to keep the origin of the universe very vague.

According to [Ishamael]'s philosophy ([Guide]), in each Age the Creator and the [Dark One|ShaiTan] have champions who lead their battle for supremacy. These champions are the same two souls who are reborn at the end of each age. The Creator's champion in the [Age of Legends] was [Lews Therin Telamon], the Dragon. The [Dark One|ShaiTan]'s champion in the [Age of Legends] was [Ishamael] who was partly trapped with him when the bore was sealed. 

! Events During the Series (Possible Spoilers)
In the current age, the champion is the Dragon Reborn, [Rand al'Thor|Rand]. By all appearances, [Ishamael] was still the [Dark One|ShaiTan]'s champion until his death at the end of [The Dragon Reborn]. Since that time, the [Dark One|ShaiTan] has tempted several of his minions with the title Nae'blis, but that honor has apparently been bestowed on one of the new [Forsaken], [Moridin].

At the end of the current age the Creator's champion, the Dragon Reborn, will face the [Dark One|ShaiTan] at the Last Battle, Tarmon Gai'don.

! References (Possible Spoilers)

# In [New Spring]
## [NS,Ch3] - Hearing [Siuan]'s [Foretelling|Weaves#f], [Moiraine] and [Siuan] know that the [Dragon|Lews Therin Telamon] will again face the [Dark One|ShaiTan] at Tarmon Gai'don and break the world.
## [NS,Ch8] - [Ellid Abareim] claims she heard [Adelorna Bastine] tell [Shemaen] that [Gitara|Gitara Moroso] had a [Foretelling|Weaves#f] that Tarmon Gai'don will come during the lifetimes of sisters now breathing.
# In [The Shadow Rising]
## [TSR,Ch9] - [Lanfear] tells [Rand] that with the [giant statue|Choedan Kal] %%ot [sa'angreal|Angreal]%% they could challenge the [Great Lord|ShaiTan] or the Creator.
## [TSR,Ch10] - When [Rand] tries to use %%ot [Callandor]%% to [Heal|Weaves#h] a dead child, [Moiraine] tells him to stop because only the Creator can give life.
# In [The Fires of Heaven]
## [TFoH,Ch6] - Seeing the two [control statues|Control Statue], [Lanfear] tells [Rand] again that they could challenge the [Great Lord|ShaiTan] or the Creator.
# In [Lord of Chaos]
## [LoC,Prologue] - The [Great Lord|ShaiTan] tempts [Demandred] with the title Nae'blis.
## [LoC,Ch6] - [Graendal] has also been to [Shayol Ghul] and been promised the title Nae'blis.
## [LoC,Ch18] - [Herid Fel] tells [Rand] that Tarmon Gai'don will not really be the Last Battle. The Wheel of Time is truly a wheel, so there are many Last Battles. No one can do what the Creator did, yet, when the Second Age comes around again the [Dark One|ShaiTan]'s prison must be whole and intact.
## [LoC,Ch23] - [Graendal] now thinks that [Sammael] may be Nae'blis.
# In [Winter's Heart|Winters Heart]
## [WH,Ch13] - [Moridin] is Nae'blis.
## [WH,Ch14] - The [Seanchan (People)] version of the [Prophecies of the Dragon|Karaethon Prophecies] says that the [Dragon Reborn|Rand] must kneel before the [Crystal Throne] before Tarmon Gai'don or all is lost.
## [WH,Ch27] - The [Borderlanders|Borderlands] believe that the Last Battle will be fought in the [Blight].
## [WH,Ch35] - [Cyndane] thinks that she would have challenged the [Great Lord|ShaiTan] and the Creator with [Lews Therin|Lews Therin Telamon], but he spurned her.
## [WH,Ch35] - [Osan'gar] thinks that if he kills [Rand] and takes %%ot [Callandor]%% he will surely be named Nae'blis.
# In [Crossroads of Twilight]
## [CoT,Ch5] - When [Perrin] passes on the scent of [Darkhounds|Darkhound], the wolves tell him that the Last Hunt is coming.
## [CoT,Ch8] - [Darkhounds|Darkhound] and wolves will fight in the Last Battle.
## [CoT,Ch24] - [Rand] thinks about the Creator's plan, then is surprised at himself as this is more typical for [Lews Therin|Lews Therin Telamon].
## [CoT,Ch24] - [Elza Penfell]'s logic for protecting [Rand] is that he must survive to Tarmon Gai'don for the [Great Lord|ShaiTan] to defeat him.
# In [Knife of Dreams]
## [KoD,Prologue] - A faction of the [Children of the Light] led by [Galad] decides that they must fight the [Seanchan (People)] and Tarmon Gai'don even if it means allying with the [Aes Sedai].
## [KoD,Prologue] - The [Aes Sedai] sworn to [Rand] feel that their oaths hold until Tarmon Gai'don.
## [KoD,Ch10] - [Seanchan (People)] lore is that the dead walking is a sign that Tarmon Gai'don is coming.
## [KoD,Ch22] - [Logain Ablar] believes that the Creator cleansed %%ot [saidin|Said] %%, not [Rand].
## [KoD,Ch22] - [Logain Ablar] orders the [Sea Folk] to march for Tarmon Gai'don.
## [KoD,Ch24] - Ghosts appear and changes occur in the [White Tower] indicating the nearing of Tarmon Gai'don.
# In [The Gathering Storm]
## [TGS,Ch5] - [Rand] hopes that [Lews Therin|Lews Therin Telamon] will help him figure out how to reseal the Bore.
## [TGS,Ch15] - [Moridin] explains his philosophy to [Rand]. There is no use in fighting the [Dark One|ShaiTan]. Every time the [Dark One|ShaiTan] fails there will be a new Age but if he wins even once, the Pattern will be destroyed and the Wheel of Time broken forever. Ultimately he must win.
# In [Towers of Midnight]
## [ToM,Prologue] - The [Forsaken], at least, believe that what the Creator can create, the [Great Lord|ShaiTan] can destroy.