Here are the Negativo as I designed them. Number 3 hasn't really been made that much, I got lazy with him.
The Negativo have developed a whole new ability known as Pesadez(Which is Gravity in Spanish), this allows them to utilize their Reiryoku and then launch it as purple energy. The energy weighs down whatever it touches. It can even manipulated to varying degrees of proficiency.
Uno- Cobra Solitario
Cobra is the Commander of the Negativo Espada and his position is well deserved. Agile and Quick-thinking Cobra strikes faster then his opponent can even react and notice they have been stricken until it is too late. Cobra is a Master Hand to hand combat expert that usually aims for soft spots (eyes, bridge of nose etc) and tries to end it in swift deadly strikes intended to slowly kill the Enemy.
Cobra has Twin Kodaichi for Zanpakutou and uses them well.
When Released Cobra grows tall and Skinny, he also gains a long pair of Claws on his finger and his teeth sharpen at the tips. If Cobra's Claws or new Fangs strike an opponent it sends NeuroToxin that will slowly Paralyze them. It takes five minutes of active motion for the Toxin to spread throughout your whole body and 20 minutes for it to dissipate. Motion is slowly Stripped from the sufferer. The amount does not matter. His Physical abilities are amplified in this form.
Dos- Guepardo Tiempo
Guepardo is the fastest of the Negativo Espada, Faster even then his Commander Cobra. Guepardo is just as strong as Cobra but because of his Arrogance and lack of leadership skills he is just the Dos, also he lost in combat to Cobra for the Title.
Guepardo is a Swordsmanship Master and has a slight weakness for Long Range Combat. Guepardo is the only Negativo espada who cannot utilize Pesadez.
Once Released Guepardo gains Black spots all across his body and his speed jumps as does the Proficiency of his Sonido. His Spots can be gathered onto a certain portion of his body, once there he can shape it into a physical form and pull it off of his skin to be used as a Weapon. Sorta looks like he just slammed his palm onto his new giant spot and slowly made a fist and suddenly pulled, the new 3D spot then forms itself into a Weapon.
Tres- Hiena Sacrificio
Okay I just have to say this. Please, please PLEASE design this guy as a Douchebag. Make him an Asshole seriously. Thats the only way to do me justice with this one.
Cuatro- Colibrí Detruir
A Counter-Attack specilist Colibri, was trained by Cobra for Hand to Hand Combat and is the second best closely following his Master Cobra. However while Cobra specilizes in attacking Colibri specilizes in Counter-Attacking.
Once Released Colibri develops a strange almost Tattoo apearing Eye on his palms. The Eye has the ability to Absorb his enemies Reiatsu whenever it comes into contact with them.
Cinco- Topo Desesperación
A Blind Arrancar Topo is very kind (kinda like Tousen to be honest). Topo specilizes in Sensing Reiatsu and can feel the flow of it and identify people by the way their Reiatsu feels. He also has above average Hearing and Smell and such. Topo has the best Reiatsu Sensing of the Negativo Espada. He is also a Cero and Bala expert.
Once Released Topo becomes slightly more muscular and has the ability to rip small pockets in the area that allow instaneous Motion, AKA Teleportation. However the Pockets can only be used by him. Long story short he can make wormholes, however he cannot block other people nor hurt them with the wormholes but can launch attacks from them. He marks the destination of the Worm Hole by ripping another hole in a nearby area allowing for later use. As long as you are in contact with Topo when you enter one of his Worm Holes you will be fine. Physical abilities Amplified.
Seis- Sapo Destrucción
When not released just your Average Arrancar with a slightly higher Reiatsu. He should be about four feet tall and skinny. Kinda wimpy looking, make him appear like a child.
After Release Sapo grows by about 1 1/2 feet. His hair gets longer and his tongue gets a sharp tip at the end for stabbing opponents. It also gains the ability to extend on his will. He can Vomit up a Goop that is extremely Adhesive and can stick to people and cause them to stick to things. His Physical Abilities are, like every other Arrancar, Amplified when Released.
Siete-Addax Intoxicación
The physically strongest of the Negativo Espada Addax is a quiet individual, she is one of the only three of the Female Negativo Espada. She usually fights by attacking viciously and savagely using her Zanpakutou.
After Release Addax gains Horns on her head that curl a little. This offers her more Reiatsu and much more physically powerful. In fact the Change in Reiatsu is so huge her power jumps beyond Hiena's in release but does not match Cobra's or Guepardo's.
Ocho- Arana Locura
The Pesadez master of the Negativo Espada Arana is a Fem-Fatale. Someone who earns your trust and then betrays it. She can use Pesdez to any number of effects. She likes to watch people suffer. She fights Gracefully using her thin blade.
Once Released Arana gains eight Arms that grow from the small of her back and each arm has the ability to grow a Blade from it's palm. Gain in Physical Abilities.
Nueve- Canario Gula The most dangerous of all of the Negativo Espada. Canario is the Final and most deadly of the Negativo. She has Instantaneous Regeneration, High Reiatsu equal to Cobra's and Guepardo's, Speed equivalent to Guepardo's and Strength that is on the same level as Addax. Unfortunately this only occurs when Released otherwise she is the weakest of the Negativo.
Once Released the only physical change that Canario suffers is that her hair changes color to Blond. Canario has the ability to pull a blade identical to her unreleased Zanpakutou from one her hairs. She can only have one of her normal Zanpakutou's at a Time and if she pulls another hair out and transforms it, it becomes a type of Ogre made of Hair that can only be killed once it has been pierced through it's "Heart". She can also scream out Blasts of Sound.