Once you reach the northern wall, turn right. Having trouble inviting friend to ultimate battle. I'm getting a bit into spoilers here, but toward the end of the series the cast is shown various clips of war and conflict not only from Universal Century, but other AU installments such as Gundam X and Gundam Wing. Mandatory information is marked with an asterisk. The place we're going is the northmost room on the first floor, so head straight up.
nest...