Lucius and a group of magical girls following the Prophet infiltrate Mitakihara Stadium during Ruri Kirishima's concert, where Chiaki Matsuda is acting as the idol's bodyguard. The group loses one member, but Lucius then defeats one of the Ninth Officio's Vindicare and takes her soul gem to blackmail the Warmaster.
Lucius contacts the Warmaster over the security radio channel. Chiaki demands an identification, but Lucius wants to talk first and asks how her “gifts” were received. She admits that the severed head and decapitated body sent to Chiaki are her handiwork and brags about how artfully she made the body look like Mami Tomoe.
Chiaki assumes to be talking to the Prophet and Lucius is startled that the Warmaster even knows that name, but quickly recovers and explains that she is not “The One Who Sees The Ten Thousand Futures”. She claims that the Prophet is pure and that she and her group are willingly shed blood in the name of their master to protect her and the world from Chiaki.
Lucius insults Chiaki's lack of appreciation for her theatrical speech and claims to do society a service by killing her. She drops her dignified act and introduces herself, insisting that Chiaki makes an effort to remember the name the Prophet gave her.
Chiaki demands her subordinate's soul gem, and Lucius tells her to have both the Vindicare squad and the Callidus stand down and to come to the stadium's baseball pitcher's mound alone t make the exchange. She admits that Chiaki did a thorough job with the security setup and explains that she is above deception and desires honorable single combat, in front of a world audience.
Lucius also explains that her subordinates are hidden in the concert's audience. She originally planned to have them kill Chiaki's client mid-song to humiliate the Ninth Officio, but will have them self-destruct their soul gems as plan B if the Warmaster refuses her demands.
Lucius tells her to be in the designated location when Ruri sings a certain song or the fanatic will give her subordinates the signal. She also warns Chiaki not to evacuate the stadium or her principal since she would call the suicide bombs in that case as well. Stating that she is looking forward to killing the Warmaster, Lucius switches her radio off.
Minutes later, just as Ruri's Waltz of the Spider Lilies starts, Lucius and Chiaki approach each other on the baseball field under loud cheers of the audience, the people considering them part of the show. Lucius taunts her opponent for not resisting the challenge to duel and claims that she will use the Ninth Officio's lust for blood to save the world from Chiaki and her Blessed Lady.
Lighting a cigarette, Chiaki demands her subordinate's soul gem. Lucius admits that she expected Kharn's successor to be even more indifferent about her underlings, to be wilder and bestial like the Sixth. While playing with the gem, she explains that subordinates are expendable and that Kharn certainly shared her sentiment, spending lives like coins.
Lucius wonders where Chiaki's compassion is coming from and ridicules her naive desire to protect her subordinates from the repercussions of fighting under her emblem. She starts a long winded rant about how horrible Chiaki is, which also complains about the smell of smoke and gunpowder emanating from her, which is allegedly worse than Kharn's vice for carnal pleasure.
Admitting that imparting knowledge on Chiaki moments before killing her is silly, Lucius finally prepares to fight. Chiaki still demands her subordinate's soul gem, and Lucius throws it past the Warmaster with full force before jumping up for an overhead cleave.
She crashes down and starts a continuous flurry of swipes until Chiaki manifests car sized iron gauntlets on her hands. Lucius jumps back and claims that the corrupted Warmaster is beyond saving for using the Blessed Lady's gifts and should submit herself to an honorable death by her blade. Fire curls around the sword as Lucius claims to end Chiaki's quest to bring the world to ruin.
Feeling that her opponent converses with the corrupted soul inside her weapon, Lucius declares she is indeed far too rotten to save. Just then, a purple flame flickers in front of Chiaki's eye and she assaults Lucius with surprising speed. The swordsman gets back on her feet and admits to a lucky hit, but is quickly struck again. The Warmaster puts her into a headlock, punches her hard and lets her fly across the field and into a wall.
Getting back on her feet, Lucius raves about her being supposed to win and that the crowd should stop cheering for the wrong side. With an angry glare, she calls forth two other magical girls from the audience to ensure her success. Chiaki mocks her about being bad at playing the hero, but Lucius explains that a hero does whatever is necessary to vanquish evil and that her comrades know this as well.
She commands attack pattern delta to charge at Chiaki from different directions. Her first subordinate, wielding two spears, is easily beat down. The second girl attacks with a spiked iron ball, but Chiaki easily sidesteps the attack and catches Lucius' blade with her gauntlets. She throws Lucius off balance and rains punches on her face before throwing her across the field again.
Chiaki catches the chain attached to the ball after sidestepping another attack and punches the girl into the ground, but is hit by the spear wielder before she can close in on Lucius. Chiaki fires a set of auto cannons at the girl, rendering her crippled and unconscious, then takes her soul gem while the other two stagger to their feet.
The iron ball wielding girl screams for her comrades soul, but Lucius tries to calm her down, promising to get it back. Despite her leader's words, the girl coats herself in a spiked armor and charges at Chiaki after falling for her taunts. She lands a hit, but is knocked down with an uppercut a moment later.
Lucius draws her guns and fires at Chiaki in an attempt to protect her subordinate, but the Warmaster simply shields herself with a giant gauntlet. Failing to convince Lucius' follower to surrender, Chiaki repeatedly slams her into the ground until she loses consciousness, takes her soul gem and faces Lucius again.
Her guns empty, Lucius takes up her sword again, the blade now bathed in crimson light. Calling Chiaki a monster worse than the Betrayer, she claims again that she is doing what is necessary, that history will see her as a hero who rose up to fight evil when no one else would.
Chiaki charges at her, and after a few blocks and parries, Lucius manages to score a surprise hit. She thrusts her blade deep into Chiaki's body and tears it out again, sending her opponent to the ground. Lucius laughs at her success and orders her remaining subordinates to begin their ascension rites and to pray for the Prophet.
She takes up an executioner's stance and asks for any last words. Chiaki laughs at her and explains that all suicide bombers have been apprehended. Mustering her strength again, she attacks the now panicking Lucius before she can bring her sword down. Chiaki catches the blade, a deep scratch revealing gold underneath the black gauntlet's surface, then snaps it in half.
Lucius falls after losing her weapon. Her eyes locked with her opponent, she screams and cries in fear as the Warmaster switches from Gauntlets to a Desert Eagle and shoots, over and over until the ammo runs out, completely destroying her opponent's lower half. Chiaki then removes Lucius' soul gem to interrogate her later.