The Irene Squad top two soldiers, Juliet and Heine, along with the rest of their squad, are sent to eliminate the Ishgar resistance located in Fiore's northern border, successfully defeating the first wave. When their leader, Irene, talks about an old folktale of Mt. Zonia, Juliet talks down on Ishgar, causing Heine to silence her. After the former returns the favor, Irene likens the comparison of the black and white angels that once battled upon Zonia she spoke of to the duo; Heine dismissing the idiocy of Juliet's comments. Irene then wonders who would be victorious in a similar fight between the two girls, only to mention it was a joke, calming their nerves. The two then watch Irene completely alter the snowy mountain's climate, both in awe of their leader's power.
The trio continues to watch the battle from afar. Juliet and Heine express their worries at the Ishgar forces' comeback, but Irene calmly states that they've nothing to fear as Bloodman and Larcade are there as well. After some clashing with the enemy, Irene orders the duo to join the ranks, something Juliet retorts too. Irene explains the arrival of the third guests, while she says she will take it upon herself on the fourth guest, causing Heine and Juliet to praise their leader's immense power. After the casting of Irene's Universe One, Juliet and Heine and the foot soldiers of the Irene Squad appear by the shore line, quickly taking out three members: Jet and Droy who succumb to Juliet's Magic while Nab Lasaro is wrangled by Heine's bands; Juliet mocking their feeble power. Juliet then asks Heine if she wants to take out Makarov next, but is quickly retorted by the female ninja, who states they should save the best for last. Suddenly, both of them feel a great Magic Power, which points to Mirajane who is currently engaged with foot soldiers. Juliet calls the Fairy Tail Mage cute, while Heine raises a bet with her partner: who will be the first between the two angels to kill her.
After hearing Zera's telepathic message, Makarov moves out the members to head towards the north. Mirajane asks Lisanna of Elfman, but she tells her that there's no sign of their brother. Suddenly from above, Juliet swoops down to attack Mirajane but she quickly evades her drop kick but she and Lisanna are covered in mucus from the impact of the Alvarez Mage's attack. Long thread-like bands quickly entangle Mirajane, which Heine is revealed to be the user of, as she signals that Mira is her target, swinging the former with bands as she twirls in the air; this upsetting Juliet as she is also her prey. Mirajane quickly slashes the bands in pieces which surprises the two girls, and then goes on to blast the two henchmen, creating a humongous explosion along the shoreline. Juliet and Heine pushed back from the force, Mirajane tells Lisanna to quickly head out with the other guild members; Lisanna wanting to stay but Mirajane assures her that she will take care of the enemy, this causing Heine to say that only a fool would challenge the Irene Squad's duo; Juliet agreeing with her partner's statement.
Juliet quickly moves to attack Mirajane with a barrage of goo bullets, surrounding the latter as the strong mucus burns her skins upon contact, causing Juliet to laugh at her pain. Heine uses her bands to stretch for the Fairy Tail Mage, electrifying them before they come in contact with Mirajane, enhancing the power to her Magical Bands' attack. Juliet follows up with a flying kick to her face which pushes Mirajane back. The Fairy Tail Mage acknowledges that she may have underestimated the two girls. Heine then mocks the Demon, saying that her strength is sub-par after she revealed all of her tricks, which Juliet snidely agrees with. Mirajane stands up while saying that everyone has a trump card, transforming into her Satan Soul: Mirajane Alegria, showcasing her raw power to the underlings. Both Juliet and Heine are overcome with fear by her form, which Mirajane explains that after the war with Tartaros; she went and took over souls from the Guild, now being able to use them at her discretion. Her power dries up some of the water along the shoreline, causing Heine to call her a monster, but Mirajane shrugs if off as she swiftly buries the two girls into the ground, knocking both out after the impact.
As the aftermath of Mirajane's tremendous power continues to affect the shoreline, she notes that the one drawback to using the stolen soul of the once Tartaros headquarters is that it vastly drains her Magic Power, going on to politely ask that the two girls stay down from their squabble. As she turns around to look at the defeated two, she sees the girls beginning to vaporize, as they revert back into their true forms of a white and black sword; this shocking Mirajane as the two girls were enchanted swords to begin with. As she wonders how there is a massively amazing Mage among the ranks of Alvarez, Irene appears and descends behind the unsuspecting Fairy Tail Mage, who is already in a weakened state from her battle.