Rubuta ci gaba don wannan sakin layi - An haifi Willius a ranar 5 ga Nuwamba 1919 a Mainz-Kostheim. Bayan kammala horon matukin jirgi, "Obergefreiter" Willius an tura shi zuwa 2. "Staffel" (2nd rundunar soji) na "Jagdgeschwader" 20 (JG 20<unk>20th Fighter Wing). A lokacin, wannan rundunar ta fara umurni da "Oberleutnant" Albrecht Freiherr von Minnigerode sannan kuma ta "Oberleutnant" Fritz Stendel. "Staffel" ya kasance a ƙarƙashin I. "Gruppe" (rukunin farko) na JG 20 wanda "Hauptmann" Hannes Trautloft ya ba da umurni. "Gruppe" an sanye shi da Messerschmitt Bf 109 E kuma ya yi yaƙi a Yaƙin Faransa a ƙarƙashin ikon "Jagdgeschwader" 51 (JG 51<unk>51st Fighter Wing). Bayan Armistice na 22 ga Yuni 1940
Na yi. "Gruppe" na JG 20 an haɗa shi cikin JG 51, ya zama III. "Gruppe" a ranar 4 ga watan Yuli. Sakamakon haka, Willius ya zama memba na 8. "Stafell" (Aikin Ƙari)