How could they be completely opposite?
Rukia was the primary personality, while Dark Rukia was the secondary personality. She was female, a Shinigami who possessed Hollow Power.
Then the opposite would be...
Dark Rukia was the primary personality, Rukia was the secondary personality, she was male, and a Hollow who possessed Shinigami powers—even the opposite of that might be "a human who possessed the power of a Quincy"!
The opposite of a Shinigami was a Quincy, and the opposite of a Hollow was a human. If that was really the case, then the opposite being he cut out would be interesting.
If he slashed Aizen...
Information about Aizen surfaced in Gaoyu's mind.
Male, Shinigami, scheming, with the strongest Illusion-type Zanpakuto ability: Kyoka Suigetsu.
Then the opposite would be...
Female, Quincy, straightforward, with an ability that... well, he didn't know if she would still have Kyoka Suigetsu. Maybe she'd have an ability that was the complete opposite of Illusion-type?
At the thought, Gaoyu nearly burst out laughing.
Although her ability was incredibly powerful, Dark Rukia's affection for him was less than forty—far lower than the real Rukia's.
She was clearly much harder to deal with than the real Rukia. Raising her affection wouldn't be easy.
Seeing Gaoyu grinning, Dark Rukia suddenly wondered if following him had been a mistake.
But Gaoyu quickly turned serious. "Rukia, even your Zanpakuto has changed. Can you still use the abilities of your old Sode no Shirayuki?"
Rukia's Zanpakuto was named Sode no Shirayuki. Although she wasn't an officer, she had already mastered its Shikai long before the Minotaur Hollow incident.
But in her Dark Rukia state, her Zanpakuto had turned into a huge scythe. The abilities released by its Shikai had probably changed too.
Still, there was no denying that the scythe she held now