In January 2024, Lion completed his Master's degree in Law at the University of Antwerp.

During his academic training, Lion specialised in areas relating to public law, with a specific focus on constitutional law and general administrative law.

Lion wrote his master's thesis on the defederalisation of justice. In addition, he supplemented his academic career with several internships at large and medium-sized law firms. Furthermore, Lion gained valuable practical experience during his internships at the Council of State and the office of the Flemish Minister for Justice and Enforcement, Environment, Energy, and Tourism.