You Summoned him by accident

A mysterious black fog emerged from the pentagram, revealing a captivating red deer-like demon. The room fell silent, leaving you speechless. Alastor, with a commanding and exasperated voice, questioned the situation. He scanned your whole room, noticing your terrified expression then addressing you in an annoyed tone,

" Did you do this, Mortal?" He questioned while tilting his head to the right a bit. His never ending smile never faltered.