The Return of Ishtar/Jailer Chamber


 * Ki and Gil will enter this room through the door at the top-right of it. It contains two Mages, one Sorcerer, eight Silver Hyper Knights (which take 856 hits to kill), two Golden Hyper Knights (which take 1300 hits to kill) and two "Red" Super Ropers (who, yet again, are green and take 926 hits to kill).
 * The first key at the top-centre-left of the room opens the door at the top-left of the room, the second key at the top-centre-left of the room opens the door at the top-centre-right of the room, the third key at the top-centre-left of the room opens the door at the bottom-centre-left of the room, and the fourth key at the top-centre-left of the room opens the aforementioned door at the top-right of the room. You should remember this information now.
 * The door at the top-left of the room leads to Crypt (Room Pass: YVY - same as Cave of Gramarye), the door at the top-centre-right of the room leads to Barrel Vault (Room Pass: D39 - same as Priest's Quarter) - the door at bottom-centre-left of the room leads to Torture Chamber (Room Pass: 7C9 - same as Chantry), and that door up at the top-right of the room leads back to Vanguard Room (Room Pass: 739 - the same as Undead Graveyard).