The person hiding in the mirror was Illuso from the Hitman Team. Fugo ends up being dragged into the mirror by Illuso's Stand, Mirrorman. Fugo then summons his own Stand, Purple Smoke. Despite Giorno wanting to find Fugo, Abbacchio decides to go look for the key, since that was their mission. However, once Abbacchio finds the key, he also gets dragged into the mirror world...
O-Only a Stand can grab the 
neck of another Stand!
و-وحده الستاند من يستطيع الإمساك
بِعُنق ستاند آخر
N-Nur ein anderer Stand könnte
einen Stand am Hals packen!
¡Solo un Stand debería
poder estrangular a otro Stand!
¡Solo un Stand debería
poder estrangular a otro Stand!
Seul un Stand peut agripper
le cou d’un autre Stand !
S-Solo uno Stand potrebbe
stringere il collo di un altro Stand!
Apenas um Stand pode agarrar
o pescoço de outro Stand!
Взять Мэн ин де Миррора за шею 
может только стенд!