After swiftly killing that man, Arvin took the man's corpse inside the rock's illusion. There first he memorized the face of the man, which was a tad bit difficult as just a moment ago he split his skull open. But somehow he managed to learn his face. Then he took out the man's clothes and wore them. He stored the man's corpse. As Arvin disguised himself, he sensed that one of the men was coming towards him. Arvin then came out of the rock, but as he did that he realized his blunder.
Till now Arvin had disguised himself countless times. And quite frankly he had been successfully able to disguise himself. But as he came out of the illusion he realized his blunder. He didn't know what this man sounds like. He had never heard the man talk. And secondly, he can't even change his voice now as he doesn't have the shape-shifter skill now. When he realized this thing, he understood that he was fucked.