A sacred cantor who curses his adversaries and turns elements from the song of creation against his enemies unmaking them is entirely consistent in story. ... this is also rather difficult to pull off ie slow... unless the enemy is already weak low on luck and about to not be a part of the world story anyway. (ie low on hit points)
An IMPRACTICAL effect would be if a snippet of the song of creation unraveled the characters past... NOW that would result in time travel like inconsistencies that would undermine your story consistency.