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...
Giorno! You have my utmost 
respect after risking your life!
جورنو! أكنُّ لك فائق الاحترام بعد
!المخاطرة بحياتك
Giorno! So, wie du dein Leben riskiert hast,
verdienst du meinen höchsten Respekt!
¡Giorno!
¡Giorno!
Giorno ! Tu as mis ta vie en péril,
et ça force le respect !
Giorno! Dopo aver rischiato la tua vita,
hai il mio più assoluto rispetto!
Giorno! Por ter se arriscado por mim,
você tem todo o meu respeito!
Джорно!