Initially operating as Baron Euro within the antagonistic Blatcher gang, Blue Euro serves under Black Express's leadership and Silver Express's manipulative influence. This role sees the character wield electric claws and deploy smoke-based concealment tactics during confrontations against the Hikarians. Blue Euro's primary function involves executing Operation Darkness schemes targeting railway systems and Hikarian protectors. Following Silver Express's defeat, the character abandons the Blatcher gang, undergoing a redemption arc that transitions Blue Euro into a Hikarian ally. Adopting the heroic identity Eurostar Blue Euro, the character integrates with European-inspired locomotives in the Hikarian universe, including the Hitachi Brothers grouping. Blue Euro's operational profile emphasizes high-speed combat capabilities aligned with the franchise's train-based mechanics.