The exact nature of Ying Ranma is hard to determine. Cologne (and Happosai, to a lesser extent) describe her as a physical manifestation of Ranma's Ying energies, given semi-substance through Happosai's magical influence. Akane promptly muses that this makes Ying Ranma into something like "Ranma's bad side come to life", suggesting that she is somewhat more than that.
Having observed that Ranma Saotome had grown more comfortable with his female form, Happosai seeks to exploit that by using magical Personality Splitter Incense on a slumbering Ranma. His hope is that this will create a female doppelganger of Ranma that he can then exploit for his own personal lusts. Instead, this female clone - Ying Ranma - simply laughs at him and then vanishes.
Ying Ranma begins to visit Ranma during the night, hypnotizing him and luring him away to join her in romantic moonlit rendezvous. This has a distinctive draining effect on Ranma, which arouses the suspicions of Akane Tendo, and leads to a confrontation between Ying Ranma, Akane, Genma Saotome, Cologne and Shampoo. Though Ying Ranma fights to keep them from intervening in her affairs, she is repulsed by the breaking of dawn.
The next night, Ying Ranma attempts to lure Ranma away again, only to find her efforts stymied by Cologne's spirit wards. When Happosai arrives, bearing incense and making vague comments about banishing her, she manipulates the old lech by promising to grant him her bra if he will take away all the spirit wards. The moment he has done so, she bewitches Ranma and leads him away to their rendezvous, with Akane, Shampoo, Cologne, Genma and Soun Tendo in hot pursuit.
After some brief treetop snuggling with Ranma, Ying Ranma is annoyed by the vocal interjections of Soun and Genma; her attack on them leads to a fight that momentarily goes her way, especially when she sets a mind-controlled Ranma on Akane, but which is turned against her when Shampoo grabs Ranma in her cat-form, sending Ying Ranma scrambling for safety in fear and breaking her hold on Ranma.
The moment Shampoo has reverted to her true form in order to avoid scaring the real Ranma, Ying Ranma attacks in a fury, but she is unable to keep Akane from slapping a spirit ward on her forehead, which destroys her utterly.
To be added
Ying Ranma is absolutely focused on the original Ranma Saotome. Cologne declares that her ultimate intent is to control Ranma, but she herself speaks only of the two of them being "together forever".
At the same time, her fixation manifests itself in a strongly romantic fondness for Ranma; her on-screen activities consist mostly of romantic activities, such as snuggling together in a treebranch under the moonlight. She repeatedly refers to Ranma as "my love", and even Soun & Genma are forced to note that they act like a loving couple when they are together, which they quip twice about it making sense given they are two sides to the same person. When she is destroyed, Ying Ranma repeatedly begs for Ranma to save her.
She shows little signs of caring about the presence of others so long as they do not interfere with her goals, but she has a very possessive streak; interfering in her desires to have Ranma to herself prompts a violent response, and she is especially hostile towards Akane for this reason.
Ying Ranma has inherited Ranma's ailurophobia, and is at one point driven off in fear by the sight of Shampoo in her cat form.
It is unclear if Ying Ranma has inherited any of Ranma's physical prowess or martial arts skills; whilst she does create a crater with a diving kick at one point, she doesn't otherwise display Ranma's normal speed or adeptness when in female form. However, she does possess multiple traits stemming from her spiritual nature.
- Telekinesis: Ying Ranma displays the ability to move objects with her mind on several occasions, including smashing open Ranma's window with her thoughts and mentally uprooting two trees to hurl them at Soun, Genma, Akane, Shampoo and Cologne.
- Hypnosis: Ying Ranma can control Ranma's mind, to the extent of setting him on Akane like an attack dog. This ability can be blocked to some degree by placing a spirit ward on Ranma's forehead.
- Ethereality: Ying Ranma can pass through physical matter like a ghost. She can also disappear and reappear, although it's unclear if this is a case of her teleporting or merely becoming temporarily invisible.
- Allergen - Sunlight: Ying Ranma does not like sunlight, and in her first hostile encounter with Ranma's kith and kin, is repulsed by the sudden breaking of dawn, which sees her fading away with pained howls. In the dub, this leads to an incredulous Genma asking if she's some kind of vampire.
- Allergen - Spirit Wards: As a spirit-type monster, Ying Ranma is naturally repulsed by paper talismans used to ward off evil spirits. She cannot enter an area that has been blockaded with such wards, and placing one on her forehead can be used to dispatch her permanently.