The Kanji for Kenzan would be 剣斬. 劍 is archaic and not used in Modern Japanese.
OMG that was freakin' hilarious! Especially the timing of some of what is said. Like when the kid is about to get attacked at around 4:25, he says (according to the very bad beta translator) "I came".
HAHAHAHAHHAAA. And "Meet the Fockers"? WTF? Plus so much more. Absolute gold, thanks for the laugh. Oh, I enjoyed watching the animation too.