He did swing it with the light infused in it (Just woke up, good morning everyone). 

And that was him using Ultima Burst to a higher level (essentially casting Ultima to a full extent)

And yea, forgot that Rune Masters could only be killed from the front, its been a long while since I played KH 2. I guess if he attacked them it would have been from behind. Im too lazy right now to go make any changes unless its absolutely necessary.