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...
You're going to die if you infect 
yourself with Purple Smoke's virus!
ستموت إذا أصبتَ نفسك بفيروس
!باربل سموك
Du gehst dabei drauf, wenn du dich selbst
mit dem Virus von Purple Smoke infizierst.
¡Dejarte infectar por el virus
de Purple Smoke es una muerte segura!
¡Dejarte infectar por el virus
de Purple Smoke es una muerte segura!
Il va être tué par le virus
de Purple Smoke, c’est sûr !
Esserti infettato col virus
di Purple Smoke ti porterà alla morte!
Ele foi infectado pelo vírus
do Purple Smoke e agora vai morrer!
Теперь он точно погибнет.
От вируса Перпл Хейза не спастись!