The Elder Scrolls V: Skyrim Special Edition

Part of the main story and thus unmissable.

Guide for the 360 achievement here.

Solution for The Fallen In The Elder Scrolls V: Skyrim

I did not write that guide. Credit goes to the author.

This is an unmissable main quest segment. Progress until the first battle with Alduin on the throat of the world and "beat" him. Simply follow the quest markers to paarthurnax and ask him about a way to find Alduin. You'll be taught a shout called summon Odahviing, whos one of Alduins henchmen. Odahviing must be trapped in dragonsreach in the jarls palace in Whiterun, which means convincing the Jarl. Balgruf will roll over to you pretty easily though. Odahviing will help you travel to the portal to Sovngarde once you talk with him, where the end of the main quest starts.

If you magically missed this via other commands, the direct command is:

~ setstage mq301 10
~ completequest mq301

If nothing happens, revert to an old save before you ever attempted the quest and/or used CAQS. then type:

~ setstage mq301 10
~ setstage mq301 25
~ setstage mq301 30
~ setstage mq301 50
~ setstage mq301 70
~ setstage mq301 120
~ setstage mq301 150
~ setstage mq301 200
~ setstage mq301 220 - whoops, forgot xbox doesn't have ccs...