Going back sometime before the war horn was blown, Matthew was standing above a tree branch, with all four of his eyes, two from his head and the other two from his snake tail locking onto the battlefield where the human army was currently attacking the ogre village by raining arrows and throwing fire magic at the village.
He had killed 3 humans on his way towards the ogre village that he assumed as the scouts that patrolled around the area to watch out for anything that might interfere with the army's siege, hence why Matthew didn't spare any aura and used the chameleon's invisible aura to make an invisible solid aura blade and kill the three scouts in only one second without even the scouts themselves knowing what had happened to them.
