Re: the burst

After a burst is resolved, It moves in reverse order, now I think refrain of denial disallows your opponent to use mugic, or nullifys it, thusly Kaz'z canon dosn't go off.

Likewise if you were playing a game with the demo deck, someone using a canon of casuality can be countered by a song of resurgence. So first the song of resurgence goes off first healing 20 points, then the canon would come second dealing 20 damage.

Hope that helps