Game Of Thrones Season 6: 8 Things You Need To Know About Tower Of Joy
3. Who Lives To Tell The Tale
Although Team Stark (...) have the clear numerical advantage, the actual battle isn't so straightforward.
Despite 10 men being involved in the fight, only two actually make it out alive: Ned Stark and Howland Reed. It's not detailed who kills whom, although there is a chance that Reed is the one to kill Arthur Dayne, given the way Ned remembers Dayne would've killed him.
Reed would later find Ned in the Tower holding Lyanna's dead body, and actually had to prise him away from the corpse. Now, with Ned's beheading on the Sept of Baelor, Reed is the only survivor from the Tower of Joy, and the only person alive who knows exactly what happened there.
For that reason he's an extremely important figure, but also an incredibly enigmatic one: he's never appeared in the series, book or show. Not yet, anyway.