"Into the heart he thrusts his sword,
Into the heart, to hold their hearts.
Who draws it out shall follow after,
What hand can grasp that fearful blade?"

I know Rand and all other characters thought/assumed this was referring to him putting Calandor into the Stone at Tear but I think R.J. intentionally mislead us on this. I think this prophecy concerns Rands battle with Moridin. "Their hearts" is Rand/Moridin, or you can swap hearts for souls since their souls are linked. Perhaps the hand that grasp the blade is Shadar hairan and links to the viewing Min had of the black hand. Obviously I think the Narishima thing was all a huge red-herring to distract us from this. Maybe it doesn't really matter and it's kinda off topic but I do think this describes the battle in the Pit of Doom. Something to think about since everyone just assumes this prophecy is irrevelant, which is what I would argue R.J. intended ;p.