Rukia Kuchiki vs. Aaroniero Arruruerie

Rukia Kuchiki vs. Aaroniero Arruruerie is Rukia Kuchiki's first battle upon entering Las Noches and is the first battle with a current Espada to take place in Las Noches.

Prologue
Rukia Kuchiki runs up a flight of stairs in Las Noches but once she reaches the top, she is shocked to see that she's in a room that looks like the outside of the palace, only in the daylight. All of a sudden someone appears right behind her and asks her if she'd like to know the reason why it appears as if she's outside. When she looks behind her, he disappears, but then reappears directly in front of a tower. The person tells her to follow him and the two of them enter the tower. The inside of the tower is in darkness and the person states that he hasn't been good with sunlight in a long time. As the person removes his mask, he states that he's Aaroniero Arruruerie, the noveno Espada. However, after completely removing his mask, his face is shown to be the same as Kaien Shiba, Rukia's old mentor. Rukia is shocked by this and can't believe what she's seeing. She asks Kaien if it's really him but thinks to herself that it's impossible since Kaien was killed by her years ago. However, Kaien confirms her question and jumps down from the pillar he was standing on. He tells her to stop looking at him so weirdly and tells her to be happy since he's alive. However, she begins to cry and Kaien tells her that if she does that he's going to look like the bad guy. Rukia then confirms to herself that this is Kaien since the feeling of being around him is the same as always. Kaien then begins to look for something and then throws her something to sit on, because they have a lot to talk about.

Kaien explains to her that the night he was killed his soul flew to Hueco Mundo, since the Hollow that took over his body, Metastacia, was one of Sōsuke Aizen's experiments and would have been equipped with that type of mechanism. Then when the Hollow fused with his spiritual body, it took on his appearance, but his will was somehow strong enough to allow him to have control of that body. Kaien then jokingly states that his "will of steel" was too strong for their calculations. Rukia gets mad at this, stating that this was supposed to be a serious story but Kaien defends himself by telling her she looked too gloomy. He then continues his story and tells her that he has secretly been working as an Espada to get his revenge against Aizen. He then tells her that the reason there's a blue sky outside this tower is because any place that has light shining on it can be seen by Aizen. Kaien then states that he's glad she was the one who came because he believes that she's the only one who can carry out the strategy he's going to discuss. He tells her that their changing locations but as Rukia runs towards him Kaien points his Zanpakutō at her.

Battle
Kaien swings his Zanpakutō at Rukia, but she dodges and he's only able to make a small cut across her cheek. Kaien tells her that she's gotten better at fighting since they last met.