So in Skyrim, when Alduin is defeated, he yells proclaiming, "Zu'u unslaad! Zu'u nis oblaan!“
Which roughly translates to “I am unending! I cannot end!” This writing is closely connected with the introduced concept earlier in the game’s script of the Season unending (”evgir unslaad”), which is the Nord concept of war, or the perception of war by their people.
Fighting Alduin is even somewhat thematic with the Clear Skies shout “Lok Vah Koor” translating to “Sky Spring Summer”– rebutting Alduin’s meteors. So Alduin positions himself not just as an eternal being, but even as the season unending, the endless harsh winter that is Skyrim’s metaphor for war. You rebuke him by literally telling him that other seasons exist.