I like how Cloud is one of the only characters whose main weapon is a Zanbato. Well, Garland's new weapon in Dissidia looks more like a regular Zanbato. And of course Cloud uses other swords as well but his main weapon is the special one and I like it how the Buster Sword is one of the only Final Fantasy weapons with a greater story.
And to ">_<": Cloud's sword is not the only thing which should show the difference between him an Sephiroth. First Cloud should have short and black hair while Sephiroth has long, white-silver hair.