Mirrorverse!Noct, who uses his retainers as sex toys and literal slaves, somehow misplaces his Ignis and goes to canon!universe to kidnap its Ignis and take him back so he could take alt!Ignis place.

Alt!Noct and Gladio ambush Ignis in Noct's appartment, overpower and rape him, and then steal him to their own universe to "train" (read: torture, rape and brainwash) him into proper obedience.

+alt!Gladio fucking Ignis and forcing him to suck alt!Noct off.
++real Noct, Gladio and Prompto finding alt!Ignis and trying to rehabilitate him, while frantically trying to rescue their own Ignis.
+++real!Ignis being horrified but unwittingly turned on by being made to serve alt!Noct.