The Necromancer Laughs - S1.E4

In the chairman's office, Ouka finds files documenting Mari's crimes... The next day, the Mock Battle Tournament has entered the second round: Kyoya's 15th Platoon against Takeru's 35th. But during the battle, Yoshimizu, Kyoya's childhood friend and platoon member, has strange black thorns burst out of her body! "I've come to rescue you, my sweet Mari-san!" Emerging from the black thorns is the necromancer, Haunted.