Wonderweiss Margela

is the only modified Arrancar in Sōsuke Aizen's army. Though not an Espada, Soul Society ranks his Spiritual Energy in the same class as them.

Appearance
Wonderweiss has a thin and somewhat child-like body. He has light blond hair, parted to one side, with the tips fanning out from his face. The remains of his Hollow mask consist a three-point tiara on the top of his head. He only has two teeth visible when smiling, freckles and bright purple eyes. He wears the Arrancar jacket with a hole in the middle of his chest, revealing his Hollow hole and the tip of a mark on his chest. The outfit also has large arm cuffs on the sleeves.

As a Hollow, he was roughly humanoid in both size and shape. Even though his body was wrapped in bandages during his birth, with several protrusions throughout his body.

Personality
Wonderweiss's personality is very childlike and possibly comparable to a child with autism; for example, when sent on a mission to kill, he instead played around with a dragonfly. He shows some hostility, firing a defensive Bala blast at one point, but quickly reverts back to his usual childlike state after doing so. In a later confrontation, Wonderweiss displays a higher level of hostility by stabbing Ukitake through the chest without any warning or provocation. Despite his childlike demeanor, he also displays some compassion by freeing Tia Harribel.

Wonderweiss does not speak in coherent sentences, only saying a few syllables at a time such as an infant would. The only coherent phrase he ever speaks is his own name, immediately after being "reborn" as an Arrancar. Kaname Tōsen remarks that Wonderweiss, like himself, is a pure being (though he remarks he doesn't quite know what exactly is pure about him) who often tend to stick together; he claims this is why Wonderweiss follows him everywhere. It is implied that he tried to restrain Gin Ichimaru from approaching Tōsen because Wonderweiss was wary of him.

Arrancar arc
Wonderweiss was first seen at his transformation into an Arrancar by Sōsuke Aizen. His original form is seen wrapped in what appears to be bandages while a barrier surrounds his body. Numerous Espada were present at his "birth", including Coyote Starrk, Tia Harribel, Ulquiorra Cifer, Nnoitra Jiruga, Luppi (still instated as an Espada at the time), Grimmjow Jaegerjaquez, Aaroniero Arruruerie, and Yammy Riyalgo.

Wonderweiss was among the Arrancar present during the third invasion of Karakura Town. He is yelled at by a bored Yammy for playing with a dragonfly instead of paying attention to the battle. This was until Kisuke Urahara intervened in Luppi's fight, as Wonderweiss tries to grab Urahara with a sneak attack from behind. Urahara senses his presence and counter attacks but Wonderweiss dodges the attack and fires a bala. Urahara dodges the attack and confronts Wonderweiss asking him what was the technique he just used as he had never seen it before. Urahara is then attacked from behind by Yammy, who explains that it was a bala blast as he fires a multitude at the fallen body of Urahara. Wonderweiss once again loses interest and just sits there. He is shortly pulled back to Hueco Mundo via Negación once Ulquiorra Cifer completes his mission.

Ulquiorra brings the Human Orihime Inoue to Hueco Mundo, and she is greeted by Aizen, who has her restore Grimmjow Jaegerjaquez's arm as a demonstration of her power. Wonderweiss serves as a witness to this and Grimmjow subsequently impaling Luppi with his restored arm (and power), simultaneously killing him and regaining his former rank.

Hueco Mundo arc
When Ichigo Kurosaki, Uryū Ishida, Yasutora Sado, Renji Abarai, and Rukia Kuchiki invade Hueco Mundo, Wonderweiss is with Kaname Tōsen, who is monitoring the intruders' activities. When Gin Ichimaru walks in, Wonderweiss stops him, due to feeling uneasy about him. Kaname explains that he believes Wonderweiss is a pure being, which is why he follows Kaname, although he admits that he doesn't know what is pure about him exactly.

Fake Karakura Town arc
Wonderweiss arrives in the Fake Karakura Town through an extremely large Garganta, interrupting the battle between the Primera Espada Coyote Starrk and Captains Shunsui Kyōraku and Jūshirō Ukitake, which surprises Starrk. Wonderweiss is accompanied by Fūrā, a Hollow so massive that it literally has Gillian masks for nails. Captain Sajin Komamura realizes that it is the same creature seen looming over the numerous Gillian who created the Negación that transported Aizen, Gin, and Kaname from Soul Society to Hueco Mundo when they were revealed as traitors.

Immediately after arriving, Wonderweiss suddenly appears behind Jūshirō and impales him with his own hand, injuring the captain and causing him to fall towards the buildings below. Shunsui attempts to attack Wonderweiss, but is hit in the back by an opportunistic Cero from Starrk sending him towards the ground with Jūshirō. Starrk comments that the arrival of Wonderweiss means that Aizen has grown tired of the battle. Wonderweiss then lets out a battlecry which causes a shockwave to break Hitsugaya's ice obelisk, freeing Harribel. The cry also seems to "blow" away the smoke left after Soifon's Bankai attack on Baraggan, revealing that the attack had no effect on him. Wonderweiss continued to scream and Fūrā vomited many Gillian-class Menos from its mouth. When the Vizard Mashiro Kuna attacks his companion killing the creature, Wonderweiss simply stares at her. Shocked at seeing his companion die, Wonderweiss then charges his Cero from his mouth but before he can fire it, Mashiro kicks him in the face. He is later seen lying on the ground with Mashiro shouting "Yay! Victory!"

Wonderweiss proves not easily defeated and attempts to attack Mashiro from the ground, but his attack is blocked and he is kicked away. He launches himself directly at her but she grabs him by the face and slams his head into the ground. Wonderweiss gets up a lets out a battlecry as he grabs Mashiro by her scarf and uses it to throw her blocks away crashing into various buildings. They both launch at each other with Mashiro firing off her Mashiro Super Cero, which Wonderweiss successfully counters with his battlecry. Mashiro immediately attacks him punching him until suddenly her mask shatters, taking advantage of her confusion Wonderweiss punches her in the face injuring her severely and rendering her unconscious. Before he can hit her again his fist is blocked by Kensei Muguruma, who states that he is not mature enough to show restraint when it comes to kids.

Kensei throws Wonderweiss, sending him flying into the buildings below. He goes to lay Mashiro down in a safe place and proceeds to talk to her for being so reckless. Wonderweiss recovers and moves to attack Kensei who then releases his bankai, the two face off resulting in a huge explosion.

Wonderweiss later appears behind Genryūsai Shigekuni Yamamoto in his Resurrección state, while he was engaged in combat with Aizen. Yamamoto senses his presence and moves to attack, to his surprise Wonderweiss catches the blade with his barehand and throws the Captain-Commander into the cityscape below. Yamamoto quickly recovers and begins to wonder why the flames of Ryūjin Jakka has diminished. Aizen then explains that he knew that he could never face Yamamoto in a one on one battle as his strength is far greater then his own. He then explains that he specifically created Wonderweiss to be the only modified Arrancar in existence. He was created for the specific purpose of nullifying the abilities of Yamamoto's Zanpakuto.

Powers & Abilities
Expert Hand-to-Hand Combatant: During battle, Wonderweiss relies primarily on his hand-to-hand combat. He seemingly possesses no formalized skill and simply uses instinctual force punching and grabbing at his opponents offensively. He commonly launches directly into battle with no care for any physical attack he may receive with no physical defensive technique other then dodging which he shown skill in.

Cero: Wonderweiss generates a Cero from his mouth. It's full potential hasn't been shown as Mashiro extinguishes his Cero while he is charging it.

Immense Spiritual Power: All of the Arrancar invading Karakura during Ulquiorra's mission to capture Orihime Inoue were stated by 12th Division observers (using spiritual power measuring sensors) to be Espada level.

Garganta: A method Hollows use to move from Hueco Mundo into the Human World. It tears the dimensional space and reveals a portal of whirling energy. Wonderweiss is able to move between worlds using this technique.

Hierro: Wonderweiss' Hierro is shown to be very strong being able to pierce Ukitake's chest with ease. He can take a beating and being thrown into buildings with extreme force without barely being fazed.

Bala: This technique hardens the users spiritual pressure and fires it from their fist like a bullet. The power emanating from his hand after his attack was pink and static-like, signifying his Bala is pink.

Enhanced Strength: He is shown to be strong enough to pierce Ukitake's chest with ease. Wonderweiss shows his considerable strength being able to critically injure Mashiro with one punch.

Battlecry: Wonderweiss can even emit a loud battle cry that shattered Hitsugaya's ice obelisk, as well as countering Mashiro's Cero. With his battle cries he seems to be able to control Fūrā; as Tōsen said, "his words have meaning".

Zanpakutō

 * In its sealed state, Wonderweiss' Zanpakutō is a large purple sword strapped to his back, about as tall as he is. The hilt resembles a western long sword rather than the more common katana, although the familiar hilt weaving is present, whilst the guard resembles an Egyptian eye. From a back view the sheath represents a zweihander or claymore.


 * Resurrección: The release command is unknown. After releasing, Wonderweiss becomes a somewhat mutated version of himself. His shoulders and thighs grow significantly larger, with the shoulders popping out upwards. His arms and legs are also altered in size, being much skinnier than before. There are five holes in his abdomen, with two or three lines within each hole, except the middle. His face is covered from the upper half by a tall mask with three small horns, which seems to make his eye sockets hollow.


 * Resurrección Special Ability: As the only modified Arrancar in existence, Wonderweiss was made with the sole purpose of nullifying Genryūsai Shigekuni Yamamoto's Zanpakutō abilities.


 * Enhanced Hierro: He is later shown capable of grabbing hold of Yamamoto's Zanpakuto blade as it is swung at him while sustaining no injury.


 * Enhanced Strength: He is also shown capable of throwing Yamamoto with relative ease.

Trivia

 * When Wonderweiss impaled Jūshirō Ukitake, he stabbed him with his left hand but his right hand was shown being removed from his back and covered with blood.
 * Wonderweiss has a strange mark on his chest, directly below his Hollow hole.
 * His surname (Margera) resembles the spanish word Manguera (which means Firehose). It would fit his function as the Arrancar created to nullify Yamamoto's Shikai.