Why does Ichigo need an Asauchi-based zanpakuto?

Zeta42 · Jun 8, 2013

Of course, storywise it's a means of repairing his bankai, or at least giving it a more or less adequate shape, akin to how Mayuri "modified" his own broken bankai. There's also been a lot of exposition. We've learnt where zanpakuto come from (and even an answer to how Kenpachi got one), and also that Ichigo's inner Hollow is his real zanpakuto spirit, while Old Man Zangetsu is his Quincy powers. And don't forget the Everything But The Rain mini-arc, which was caused by Ichigo failing his first attempt to bond with an Asauchi. That's quite a lot of stuff revolving around a seemingly easy problem of getting his zanpakuto back, don't you agree? However, what is it going to gain us in the long run? Ichigo will have a proper zanpakuto, made from an Asauchi, but why is it necessary for him to have one in the first place? Aside from learning about his origins, how will he benefit from such a sword?