While the fight between the Zero squad/division going on, Ichibei and Yhwach fighting after their meeting 1,000 years in the past. Ichibei uses both of his Shikai and Bankai, which gotta be the most broken Zanpakuto. I doubt that Aizen back in the Fake Kurakura arc could have won even with being immortal. If you like the video and want to see more please like and subscribe
