The power scale is gonna be inaccurate, as I am still figuring out Grey's storyline and his relevance in the main story, (Deletionverse). Don't ask any questions about this please it might not even happen.
This cannon is capable of giving a being with "Planetary Level" defense severe 5th degree burns and can very easily be lethal to them even if they survive the blast due to the exposed muscles and exposed veins following the attack btw.
