The stage 7-9 like myth 1. In this stage, do a few quests and you will battle Goddess Lunia. Before killing Goddess Lunia, she will self-destruct and stage will end. Or if you go 7-9 with a Sieg or Arta, you will battle against a secret boss, the shadow's nightmare. When done solo, a level 300 Krieg will appear multiple times to help with bosses, such as attacking Goddess Lunia.