In the King's Mausoleum, there is a very dark room you can go to that has several stone faces hanging from the ceiling, and a stone pedestal in the center of the room that can be set on fire to brighten it (to better hear this Easter egg, you should not light it, and turn off the music). If you stand in front of the pedestal, several distorted voices can be heard throughout the room. Reversing them reveals that they are actually audio clips of the Radio Operators from the English dub of Armored Core 2: Another Age.