When the swords hit, the demon's black ball of oblivion came down on a chair nect to him, removing it from existence completely. When the light appeared, hi screamed in anger or pain or both, covering his eyes.  The demon snarled and, still blinded, turned to you, obviously realising you were not moving aside. He seemed to be pretty sturdy. It would take some effort to vanquish him. 

Meanwhile the IT guy had got whoever he wanted to call on the phone and was whispering furiously about a demon and where he was.