Walter is one of the characters featured in the crossover with the Japanese trading card game Last Chronicle. His card, featuring an illustration drawn by Ikumi Fukuda, was released in the Rebel Contract Deck[2], which also featured illustrations of Dagda, Nanashi, and Jonathan.
↑"Special III: History of Tokyo & Mikado: ■Year 2037 (Year 1474, Gregorian calendar) *Flynn is born." Shin Megami Tensei IV: Apocalypse. Flynn is the same age as Walter, therefore he was born in either 2037 or 2038, since he'd have to be 18 years old at the start of the game.
↑"Shin Megami Tensei IV Final ‘Last Chronicle’ Card Illustrations" Reggy, [1]. Published April 7, 2016. Retrieved November 9, 2023. Persona Central.