Recently released in Japan, Namco Bandai's Tales of Hearts for the Nintendo DS features a slew of support-character cameos, including everyone's favorite gnosis killing machine, KOS-MOS.
Hearts features cameos from a wide variety of Namco Bandai's characters from previous Tales games, but KOS-MOS here comes straight from the ill-fated Xenosaga series, which towards the end featured some of the best cutscenes of any RPG anywhere, but little else. KOS-MOS jumps into play, showering your enemies with bullets before jumping back into the support character limbo off-screen. Poor KOS-MOS. Her time came too soon.
You Got Xenosaga In My Tales of Hearts! [Siliconera]