Mala Suerte!2 "El Monstruo"

Wounded but grinning, Ikkaku chases Edrad through the streets with his Zanpakuto and needles him for keeping his own sword sheathed. Edrad answers that an Arrancar's Hierro makes his hide as tough as armor, so he could win bare-handed, yet a sudden slash braced with the scabbard forces him to half-draw his blade to save his arm. From the sidelines, a baffled Keigo asks why Yumichika will not help, and Yumichika explains that Ikkaku is simply savoring a worthy opponent for the first time in ages and would refuse any aid, adding that his friend will die happy even if he loses.

Edrad reads Ikkaku's rhythm as predictable, attacking left with the sword and guarding right with the sheath, and moves to exploit the pattern. Ikkaku turns the trap around, quietly swapping the scabbard into his left hand so Edrad blocks the wrong weapon, then opens a gash across the Arrancar's face with the sword in his right. Edrad, cut but alive, realizes the whole predictable style was bait and that Ikkaku fights for the thrill rather than the win. Ikkaku spits out two knocked-loose teeth, works out that Palma Plancha is a fist packed with spiritual energy, and vows to keep pounding until Edrad releases. Conceding he underestimated the Third Seat, Edrad promises to teach him never to treat an Arrancar as sport and enters his Resurrección, Volcánica, rising with massive arms, towering shoulder spikes, and a helm of white armor before introducing himself in full.

From Volume 23, MALA SUERTE!, of the Arrancar arc, and adapted into Episode 118, Ikkaku's Bankai! The Power that Breaks Everything. The Spanish subtitle El Monstruo means The Monster. The chapter delivers the first look at an Arrancar Resurrección in the Karakura battle, Edrad's Volcánica.