go to the news archive section and read the article of the january28 2002. u will read that Helene Sheeler from midway had mentioned :HIDDEN MOVES and NEW WORLDS! and hidden moves in mkda means new konquest missions! and if u want my opinion i would say that the hidden moves are in the empty coffins(cause there r 21 characters/21 empty coffins)may be if we perform something or finish something and go quickly to the krypt we gonna find'em full.
It could be that empty koffins are not really empty, there may be nothing in the koffins, but maybe by opening them, every character gets a new move, and we haven't discovered them yet... Or something like that... But whatever, I'm not gonna go crazy trying every button combination I can just to try out this idea...