 At the end of the war he was serving with the 39th Reserve Division in the Vosges.After the war, Lion joined a volunteer division, Freikorps Epp, taking part in the dismantling of the Bavarian Soviet Republic.The last military rank he hold was that of a Generaloberarzt a.D.

After being demobbed from the army in 1921, Lion worked as a doctor at the spa resort of Oberhof.