There's also this possibility:
The cycle is a helix; a periodic repetition on top of a *nonperiodic* progression. Light and Dark ages alternate, but on the whole the world keeps getting Lighter. The Dark keeps getting easier to beat, even during the wars when it's supposedly fated to win. Recall that Moagim's death sets an "uneasy precedent" that, even if the Dark wins, the Leveller can still die in the battle. We might infer from this that, prior to that, the Leveller always survived when the Dark won.
So the historical pattern might be:
Late Axe Age--The Dark wins, handily. The Leveller survives and runs a Dark Age.
Age of Reason--The Light wins, handily. Tireces survives and does good stuff.
Wind Age--The Dark *barely* wins. Moagim doesn't survive, but enough other Dark forces are left to make it a Dark Age.
Wolf Age--The Light has a crushing victory. Not only does Connacht survive, but he's able to take down the Dark *and* the Trow.
Sword Age--The Dark *almost* wins, but the Light manages to triumph in the end. The Age will perhaps be an unsettled one, with repeated invasions by Dark lords and evil forces, but so far it's clearly better than a truly Dark Age.
So we might expect that the Dark will continue to grow weaker and weaker over the next few millennia, until every age is a Light one--it's just that they alternate between slightly dangerous ones with a smidgen of Dark influence, and completely happy and peaceful ones with no Dark influence whatsoever.
--SiliconDream
