Fairy Tail season 3 epsiode 6: Arlock summons one of the Yakuma 18 War Gods known as Ikusa-Tsunagi to slaughter his own men in order to draw out Zeref, revealing that this was the true purification plan all along. Natsu is enraged and faces Ikusa-Tsunagi in a one-on-one battle, eventually coming out victorious while later learning of the averted future that Rogue went on to rule.
