There are only SIX swords contained in the whole of the First Tsurugi's sword compilation. One is the big ass main blade that can turn wider for battle mode and close for combining, a simple one that fits in the bottom of the main blade, two saw-like blades to fit in both sides of the upper part of the main blade, above the simple blade, and two foldable-handle blades to fit in on either side of the combined saw blades and simple blade, as if to strengthen the hold on the massive weight of the whole combined sword. Here's the pic, it clearly shows SIX swords.

And on topic, yeah, it's called "Omnislash version five". Apparently there are already four previous versions of Omnislash, the first is in-game, some from KH/KHII, and the most recent on AC.