Ah, forgot to add that part as well. The blades all repeat a single strike before dissapating. They exactly mimick the casters attack, real-time duplication, and if any blade happens to reach the circle's center (except the main blade), it dissapates as well. It also happens if the blades collide with each other, though that shouldn't happen if the blades are shorter than the circle's radius.
Think of it as this - when the spell is activated, the duplicates appear, all their pommels lying on the circles perimeter thogether with the master blade's pommel as well. The only diffrence between all the blades is the point they orginate from. Otherwise, they all make the same movement - the same stab, same clowckwise or counter-clockwise slash and ect.