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...
Fugo must be in here, too.
لا بدَّ وأنّ فوغو هنا أيضاً
Fugo muss auch
irgendwo hier drin sein.
Fugo también debe estar por aquí.
Fugo también debe de estar por aquí.
Fugo aussi,
il est quelque part ici.
Anche Fugo dev'essere qui, da qualche parte.
O Fugo também deve estar aqui dentro.
Значит, Фуго сейчас где-то тут?