Saint Oratorio is a destructive and incredibly dangerous spell that consists of an intense bursts of raw magic that can annihilate anything in its path. It is specifically meant to be used in concert with the OutRage.
The spell was being developed prior to 2014 by the "Saint Oratorio Project".
Sol Badguy designed Junkyard Dog MK III with a secondary function to transfigure into a long-range cannon that can fire a weak version of Saint Oratorio. However, the backlash from unleashing this spell is tremendous, causing it to not only cause significant damage to the target and environment, but the user as well, which is why Sol uses it sparingly.