The Demon Sword Master of Excalibur Academy, Vol. 6 (light Novel)

When Leonis and the rest of the eighteenth platoon return from their mission to Necrozoa, Riselia hammers him with questions about his past. Is it time for him to reveal his true identity? Meanwhile, a group of armed mercenaries from the Sakura Orchid plot to invade the Seventh Assault Garden. To stop her former compatriots, Sakuya will have to seek out the power of a Dark Lord (Leonis)!