I put humor as a 4...
Because of your choice of music.
Man, you got to change that. As it is right now, it seems like a story very young children would want to see. And maybe that's what you were going for, though I was thrown off by all the killing.
But I think this has the potential to be a very great story not only about action and fighting, and mystical swords... but also about drama, and love and passion. It has room for character development, internal conflict as to what the sword has done to him exactly. You already got suspense in there.
Anyway, this trailer is seriously almost perfection. Maybe you just ran out of room to put good songs (I've had an experience similar to that where I wanted more serious songs but just didnt have space).
I'm still going to fiven this though, but please follow my advice. KUTGW!! P.S. - Sound effects were good which is why you got a 7.