Czeslaw is a young child who gained immortality aboard the Advena Avis. Because of the way his guardian, Fermet - who also gained immortality in 1711 - treated him, he is extremely afraid of the other immortals and wants to "eat" them all before they can "eat" him. Despite being around 230 years old in 1931, his mind is very immature as he will never reach puberty, the 'cure-all' elixir eternally deeming his body a child's.