Powers and Abilities

Ofcourse, I will talk about Yoruichi's... 

Feline Transformation: 

Yoruichi possess a unique ability which allows her to shape-shift into a black cat at will. How she alone out of all Shinigami is capable of this is yet unknown. She has apparently possessed the ability for well over 100 years, and it's apparently known to others she knew from that time. She apparently has no set time limit on the transformation as she had been in the assumed form for over 100 years. In cat form, Yoruichi can still channel her spiritual energy and move at incredible speeds, though she is physically limited by the form. Her transformation also allows her a complete disguise, as her voice in this form is deep enough for most to assume she is a male. This, of course, leads to awkward situations when she reveals her true form.

Hakuda Master: 

Yoruichi as former Commander-in-Chief of the Onmitsukidō is one of the most accomplished hand-to hand combatants in Soul Society. Her mastery of the art form is so great that she uses it exclusively as her form of combat of choice forgoing the use of a Zanpakutō altogether. She has been shown to take down nearly 50 Onmitsukidō members with only Hakuda. She has been shown taking on the likes of Espada-level Arrancar as when she brutally defeated Yammy and is even regarded by the 4th Espada Ulquiorra Cifer as highly dangerous. In addition, she was able to combat three Shinigami captains and four lieutenant level and above opponents at the same time with Hakuda without receiving any notable damage.

• Raiōken (雷王拳, "Thunder King Fist"):

A hakuda technique involving a serial of rapid punches. Using this technique, Yoruchi was able to severely crack Aizen's first form and destroyed a portion of Karakura Town in the process.

• Taketonbo (竹蜻蛉, "Bamboo Dragonfly"): 

A hakuda technique involving an axe kick while in mid-air. Yoruichi attempted to use this technique against Soi Fon.

Shunpo Master: 

Considered to be the most proficient Hohō master ever in all of the Soul Society, Yoruichi is highly skilled in the use of Shunpo, a high speed movement ability. Though this is by no means a unique skill, as most seated officers are capable of performing it to various degrees, Yoruichi holds the title "Flash Goddess" (瞬神, shunshin; "Flash Master" in the English version), because she has mastered this ability to such an extent that she can appear to be in several places at once and wipe out an entire Onmitsukidō squadron in seconds. She can easily close tremendous gaps of distance in the blink of an eye while remaining undetected, as shown from her ability to surprise Byakuya, who is one of the most proficient in the art as well. She has mastered all of the Onmitsukidō's speed-oriented techniques and even created some of her own, such as Utsusemi (空蝉; cicada, referencing their molting).The full extent of her abilities remain unclear, but she was able to outrun Byakuya while carrying an unconscious Ichigo over her shoulder, where she was able to perform around 300 steps before feeling tired from 100 years of being out practice. She is so fast that Soi Fon could barely keep up while Yoruichi was still holding back. It is revealed that she can still perform Shunpo even while in her cat form. Unfortunately for her, she is not as fast as she is in her true form.

• Utsusemi (空蝉; Cicada, referencing their molting): 

Way of Onmitsu, 3rd of the Shihou. It allows for a movement at great speed, leaving at least one tangible after-image behind. Byakuya Kuchiki states that she taught it to him.

Shunkō (瞬閧, Flash Cry): 

An advanced technique that combines hand-to-hand combat with Kidō. She fights by surrounding her back and arms with pressurized Kidō. The keisen uniform has no back or sleeves since they will rip apart when it is activated. The technique can allow her to instantly neutralize an opponent's movement, apart from enhancing their arms and legs for battle. The Kidō itself can also be controlled and fired at opponents from her body, and can be used to create massive explosions. Yoruichi's version of the technique was developed and studied by her a century ago. Therefore, the technique is complete. Unlike Suì-Fēng's version, the compressed Kidō is visible.

• Hanki (反鬼, Reverse Demon):

This technique is an ability Yoruichi uses during Shunkō, which nullifies an opponent's Kidō by hitting it with a Kidō of perfectly opposite speed and energy. The ability can even neutralize an opponent's movements.

Master Assassin: As the former Commander-in-Chief of the Onmitsukidō, Yoruichi is one of the foremost masters of the art of assassination. She has repeatedly shown impressive skill in staying hidden and unseen. When necessary, she can effectively exploit having an advantage against an opponent or hiding her presence. Even one as intuitive as Aizen was completely taken by surprise and just as easily subdued.

Master Strategist: As the former head of her clan and ex-commander of the Onmitsukidō, Yoruichi has shown herself to be a capable leader. Repeatedly, Yoruichi has shown to be insightful and crafty, quickly capable of understanding any situation that presents itself and adjust to it effectively. Upon learning that Ichigo would go to save Rukia no matter what, Yoruichi began making preparations of her own by training Orihime and Chad.

Zanpakuto:
As a former captain of the Gotei 13, it is known that Yoruichi possesses a Zanpakutō and has achieved Bankai, but she relies nearly exclusively on Hohō, Shūnpo, and Shunkō. Although she doesn't carry it at all in the current time, she is shown wearing it in the past. It resembles a kodachi or wakizashi which she kept sheathed horizontally behind her on her lower back, similar to how Soi Fon carries hers in the present day.

In Short, Yoruichi is really strong with or without the use of her Zanpakuto.