Board Thread:Off Topic/@comment-25076409-20140712184109/@comment-6881629-20160111175240

Normally with no mods Alduin levels along with you i think, the lowest he can be is level ten and the highest is level one hundred. You shouldn't (unless some mod allows it or you try commands) be able to take followers with you.

I just fought him a few days ago on my latest playthough, lots (and lots) of arrows and Dragonrend, the three heroes did a pretty good job of tanking him.