Bleach: Thousand-Year Blood War - The Calamity Episode 9 comes after a month-long break, and the extra time clearly went into the animation. The episode opens with Yhwach’s eyes sweeping across the sky over three worlds. Every attack thrown at Yhwach proves ineffective. The sky is still closing, and time is running out.
Ishida manages to shoot him with the silver arrow. After that, Ichigo strikes him with his old Zangetsu while Grimmjow, Shunsui, and their team attack Yhwach as well from different directions.
Three realms, one enemy

Bleach: Thousand-Year Blood War - The Calamity Episode 9's battle takes place in the Living World, Hueco Mundo, and the Soul Society. Ichigo and Ishida attack, but nothing happens. Yhwach says he has nothing to tell the enemy, and then he attacks with a big blast. Meanwhile, Soi Fon, Shunsui, and Hitsugaya destroy eyes only to see them reproduce.
In Hueco Mundo, Halibel and Grimmjow are destroying the current foes, while other Hollows are running. Nel, who is still a child, watches the clouds. Later in Bleach: Thousand-Year Blood War - The Calamity Episode 9, Soi Fon, Byakuya, Grimmjow, Halibel, and Ichigo attack Yhwach, but their attack never succeeds. He shatters Ichigo's sword and tells Ichigo to fear.
Ishida’s plan in Bleach: Thousand-Year Blood War - The Calamity Episode 9

As the fight continues, Ishida remembers their first fight against the Menos Grande. He instructs Ichigo to shoot Getsuga Tensho from behind him while he fires his own shot. The two moves become one and are fired at Yhwach. This scene in Bleach: Thousand-Year Blood War - The Calamity Episode 9 references an earlier moment in the saga.
After their attack, Ishida shows Ichigo a silver arrow tip. The arrow, once it reaches Yhwach's blood, puts him in a weak state. It is essential for the arrow to reach Yhwach's heart, so Ichigo agrees to dive into him one more time.
Three gaps in the sky

At the Research Institute, the warnings increase. Sky coverage reaches 74 percent, and then 92. Akon suggests feeding Hollows to the amplifier and using a Hollow-type beam against Yhwach. The Research Institute has a more important role in Bleach: Thousand-Year Blood War - The Calamity Episode 9 than usual.
The sky remains at 99 percent only due to Ganju, Nel, and Iba. Ganju jumps at an opening and takes sand to fill it up. Pesche and Dondochakka throw Nel, and she does the same to the gap in the map of Hueco Mundo. Iba stops the last gap. After that, the amplifier is launched, and Yukio controls it.
Arrows with final slash
The silver arrow is already in Yhwach's chest while he talks about merging worlds. Earlier, Ishida had fired the arrow. Grimmjow bites him, and then the scene goes to Urahara, hinting that this is a trick that gets forgotten.
After that, Shunsui hits Yhwach with the arm of the Soul King. Soi Fon and Hitsugaya helped him reach that far. The episode ends with Ishida stating that it's time for Ichigo to act.
The last attack is made from three directions. Grimmjow strikes with Pesche and Dondochakka, while Shunsui does the same thing with Ryunosuke. Meanwhile, Ichigo strikes from the front. Yhwach takes Ichigo's sword and destroys it, since it's apparent that Ichigo uses an old Zangetsu this time. A slash follows as the title card appears.
The connection between Yhwach and the Quincies is broken. Aizen, Isshin, and Ryuken don't appear in this episode, and that is the end of Bleach: Thousand-Year Blood War - The Calamity Episode 9.