PS VitaPS4 Valkyria: Azure Revolution ‘Prologue Demo’ launches late December in Japan This one will let you carry over your save data. If you missed out on your chance to get the Valkyria: Azure Revolution ‘Battle Demo Ver. 2.0,’ Sega will release a ‘Prologue Demo’ in late December. The Prologue Demo, presumably the final demo, will allow users to carry over their saves into the final game when it launches in January.If you missed it, catch the latest trailer here. Valkyria: Azure Revolution is due out for PlayStation 4 and PS Vita in Japan on January 19.