Alduin's Bane

Overview
Upon retrieving The Elder Scroll (Dragon), the Dragonborn will need to go to the Time Wound at the summit of the Throat of the World and learn the Dragonrend shout that can finally defeat Alduin once and for all from those who created the shout in the past.

Walkthrough
Upon completing the quest Elder Knowledge, you collect an Elder Scroll. You will need to return to Paarthurnax atop the Throat of the World and read the scroll at the time wound. When equipped, a cinematic scene will begin. You will see an image of past heroes. You will then learn all three words of the Dragonrend shout, which will be used to defeat Alduin. Once you come out of the vision, Alduin will attack you. Use Dragonrend on Alduin to make him land on ground, where you can then begin to damage him. After Alduin is defeated, he will fly off and escape.

Scenarios

 * Depending on difficulty, Alduin has roughly 100 - 250% resistance to both frost and fire magic and only shock damage will harm Alduin.
 * If you have completed the Quest for the College at Winterhold and retrieved the Staff of Magnus bring it with you to the Throat of the World with enough Soul Gems to recharge it fully. It will take two full charges while attacking Alduin from behind but since the staff drains Magicka immediately, then it drains Health, once the Magicka is depleted it will make swift work defeating him.
 * It is possible to trap both Paarthurnax and Alduin on the ground when they are attacking each other. If this can be done, stand behind Paarthurnax and use him as a shield and pick away at Alduin's health. Use Dragonrend whenever you can and the two will become stuck on the ground fighting each-other instead of the character.
 * Like all dragons, Alduin's breath attack relies on his magicka pool. A barrage of lightning type spells can potentially deplete his reserves to a point where he is helpless on the ground able to only do physical attacks.
 * During the fight between the Nord Heroes and Alduin, Alduin might get pushed toward the Word Wall when he steps over the corpse of the dead Dragon nearby. This causes Alduin to be stuck facing the Wall and trying to turn around. However this does not affect the game much, and Alduin will still be banished as usual.
 * You can stop Alduin from shouting the meteor storm by using Dragonrend as soon as you see him then conjuring a Storm Atronach; this can prove useful for lower-level players.
 * A good trick for low-level players is to always stand behind Alduin. He will always perform his tail bash attack, which is much less damaging than his bite or breath attacks.
 * The Shout Marked for Death is the best shout to use for low level players and it's advised to get all three first as in only getting one or two of the whole shout might not take full effect until forcing him to land again by using Dragonrend.
 * Summon something (e.g. Dremora, Atronach, Spectral Assassin) to distract Alduin whilst you attack him from the rear
 * Shadowmere also distracts Alduin during the battle allowing time to heal etc. Tip:Grand Healing will heal all allies.
 * Adventurers may also Summon Durnehviir at this point to witness a three way dragon battle(warning:this will leave you unable to use Dragonrend for some time).

Bugs
It is possible that Alduin will take no damage no matter what.

This is caused by attacking Alduin before the talking is over.

On Xbox 360 to fix this bug simply exit the game and go to console settings/memory. Once there press y and reset your system cache. Be warned that you may have to do this several times because you can cause it to glitch again the same way.

Trivia

 * The cinematic part in this quest when you read the Elder Scroll at the Throat of the World is the only visual representation of the Dragon War, besides the books that can be read in the game.

Behind the scenes

 * Unless otherwise stated, the information above was obtained from in-game play or from The Elder Scrolls V: Skyrim Creation Kit.