My Otherworldly System

"I shall Conqueror all these plains to become stronger" Andrew Sheman thinks aloud as he stands atop a hill. Earth is hit with otherworldly energy giving people superhuman abilities and powers; animals and plants start to mutate into horrendous creatures. Years after we find Andrew Sheman, a small and weak high schooler who is forced to fight mutated creature. During one of his missions, he ends up dying, but through a miracle, a powerful system awakens in him giving him the power of gods and demons.