It came as quite a surprise to me when Rand’s heron-marked sword was destroyed during the climactic battle with Ba’alzamon at the end of The Great Hunt. The sword has been something of a talisman for Rand ever since he left Emond’s Field, and in a remarkably complex way. On the one hand, Rand imbued this gift from Tam with his deep desire and need to believe that Tam was his true father—for him, carrying the sword was proof and symbol of their bond as father and son. But the heron-marked blade had a very different significance to those around Rand, drawing often-unwanted attention to him and marking him as a dangerous man and a blade master. The fact that Rand is neither of these things caused a certain level of danger for him, but then again, it’s not so much that he isn’t a blade master—it’s that he isn’t a blade master yet. And as for being dangerous… well, a stranger might be deceived by the looks of a young shepherd (unless they know the Aiel, anyway) but those close to Rand certainly know better.
And then of course there is the verse in the Prophecies of the Dragon, which alludes to a completely different purpose to the mark of the heron, one that will identify Rand as the Dragon Reborn. These, of course, are the two scars burned into Rand’s hand by wielding the sword while channeling.
In this way, the heron imagery, and indeed the sword itself, at one time separate Rand from his true identity as the Dragon Reborn and at the same time irrevocably tie him to it.