[quote=@Raineh Daze]
I'm wondering how long until Guts needs a new sword because he's hit something that it: A) can't cut, and B) is durable enough to shatter it.
[/quote]

A several hundred pound mass of iron won't just shatter when it hits something. On top of that, the Dragonslayer's been enhanced to cut through magical stuff. Guts isn't gonna need a new sword anytime soon.
If anything, I could see it getting augmented if I run into a good enough smithy.