Because Maka simply has more going for her
Maka possess a special wavelength that acts as a bane against dark forces such as magic, demons, and even likely immortals. This wavelength also allows her to utilize enhanced forms of the Witch-Hunt, allows her immunity to certain magics like Arachne's magic, direct influence from the black blood, and madness to an extent. She can voluntarily transfer this wavelength to her partner, to others on her own with physical contact, or through Soul's piano.
Maka possess a rare soul type in which allows for flight. To enable this ability, she requires the usage of a Death's Weapon to utilize advanced magical-like powers. By being on the same page with partner during soul resonance, she can manifest wings onto her weapon form.
A trained meister, has an excellent level of athletic ability in which surpasses Soul.[63] She was also able to run 100 meters in 8.92 seconds. Her athletic ability was renowned enough to be compared to Patty Thompson when she showed amazing physical ability herself. Maka is a also surprisingly durable individual able to withstand Crona's Screech Alpha, punishment from Free even after the later even slammed her with his Ice Shackle Bullet spell and overpowered her with his own martial arts and physical abilities as was still able to fight. She was also able to take Arachne's hits within her disembodied from
Soulās piano allows the user the capability of transmitting other wavelengths via sound, enabling special phenomenons such as Soul Resonance even within a Magnetic Field, in which disrupts the senses required to usually do so. Doing so, however, requires a user(a Meister with great Soul Perception abilities. This can be done within their own "soul dimension" within their weapon forms per being part of them or for those whom achieved a Death Scythe status, it can also be done independently with a transformation into a keyboard in their weapon forms, though the capability is greatly diminished compared to being partnered up with a Meister.
The piano can also influence the use of the Black Blood, allowing it to harmonize with another possessor of the Black Blood and/or create a Black Blood Armor for an individual's Meister as well as grant vast regeneration abilities.
Power of the Spider Queen
The Power of the Spider Queen (åć®"ččć®å„³ē", Chikara no "kumo no joÅ") describes the set of songs Soul was able to use after consuming Arachne Gorgon's soul. Gaining Magical-Like Powers, his Wavelength Control became more advanced was capable of performing:
An improved Soul Meditation
Soul Hack (After sending the Wavelength of a given object controlled by a single individual (i.e the Bits controlled by Moonlight), the user of Soul's Piano can send a wavelength and commandeer the object under their control.)
Soul Adagio (Working akin to noise cancelling, Soul's Piano can play a wavelength that is opposite of his target's own. When the opposing Wavelength or the "Antiphase Wavelength" reaches an opponent, it cancels out their abilities. This causes the target to be in a lethargic, trance-like state.)
Maka can disarm ruby by not only taking away her scythe but her aura.
Demon Scythe (éé, Magama): With Soul Eater as her weapon partner, she is able to take advantage of the plethora of capabilities in which result from their Soul Resonance as well as other abilities. After becoming a Death Scythe and combining it with his sound abilities, it is known that the result is that it greatly enhances her already proficient skill, Soul Perception.
Black Blood (é»č”, Kokketsu) (Former): While in resonance to Soul, Maka has access to black blood with Soul Eater. Under it's influence, she has greater strength that makes her capable of tossing Crona into a arch structure, destroying it in the process. She also managed to manhandle Crona, whose strength due to Ragnarok once overpowered herself. Maka was also able to take fatal attacks from the Black Sword transformation with only minor wounds as well as being resistant to stabbing related attacks. This can also increase her healing ability, even surviving being impaled by Asura himself.
Black Blood's Madness (é»č”ć®ēŗē, Kurodji no HakkyÅ) (Former): In this state, the Black Blood's Madness gives her a wavelength similar to Crona. With this Madness, the Little Ogre stated that it doesn't let Maka feel fear at all. With this Madness, her fighting style becomes more erratic.
Black Blood Armor (é»č”ć®é§, Kurodji no yoroi) (Former): This ability is one of Maka's major advantages with the Black Blood and Soul Resonance. Formerly, this dress was prematurely created during her fight against Arachne, giving her a boost in defense enough to withstand Arachne's powerful web attacks as well as enable her to easily utilize the Demon-Hunt technique in addition and allowed her to kill Arachne. After Soul pulled the Black Blood in full blast, this created a new and more formidable dress armor, allowing her flight even.
And before you ask, Rubyās silver eyes canāt counter the black blood. Silver-Eyed Warriors have powers that are fueled by strong desires to preserve life. According to Maria, itās emotional, much like Semblances.
As preservation is considered an extension of creation, Silver Eyes can work against Grimm as they are manifestations of destruction (which black blood isnāt). Legend has it that Silver-Eyed Warriors are able to strike down Grimm with a single look. According to Maria, Silver Eyes can turn Grimm to stone, blind them or vaporize them. In "End of the Beginning", Ruby Rose is told that when she unleashed her power, she "froze" the Wyvern atop Beacon's tower. It is later known that she did so by turning it to stone. Although immobilized, the Wyvern was not killed outright by Ruby's powers, and remains alive, continuing to draw Grimm to the area. In the past, Maria used her eyes on a Nevermore, turning it into stone. Some Grimm, such as the Leviathan, are not as badly affected, and display some resistance, as the Leviathan was only encased in stone and not completely turned into it
Black Blood (é»č”, Kokketsu) is a synthetically made and weaponized bodily fluid created by the witch, Medusa Gorgon. The Black Blood, unlike regular blood, is weaponized and can either harden or soften depending on the user who is controlling the Black Blood. The hardening and durability of an individual with the Black Blood, however, varies from individuals to individual. However, those with Black Blood are blessed with powerful healing capabilities and can heal from grievous injuries.
Ruby literally has no way of winning while Maka literally has a insta win button (also is technically a 2v1, Makaās scythe is not only alive but can take human form)