Cerveau is a new Engineer to the Repliforce, but a brilliant Reploid thinker. His interests and skills lie mostly within the field of weapons development, though data analysis seems to come naturally to him as well. He is amazed by the level of intelligence Ciel has attained at such a young age, and treats her as his superior, despite him being several decades older. He is something of a worrywart, always relieved to see that his comrades have returned from their missions safely.