Aisha's sword doesn't seem to be limited in use.
It rather feels to me that Welf swords have that limitation.
Bell's blade was forged by Welf's latest master and that blade doesn't seem to have limited use either.
My guess is that Welf is a genius blacksmith in the making. His swords break because he infuses them with magical attributes to a level never seen before, but he has yet to find a way to make them more durable. When it happens is when he approaches God like mastery of his craft.

But it's possible I overlooked other weapons being shortlived.