Matthias and Ricardo

The Middle's hierarchy system features at least four major ranks, which do not appear to contain sub-ranks. The ranks are as follows:

Little Brother/Sister Young Brother/Sister Big Brother/Sister Great Brother/Sister While there are multiple ranks within the Syndicate, they do not seem to call for any difference in how members treat each other, as in-group relationships are built on mutual respect, care, and trust that succeeds any power structure. Instead, there exists a natural tendency for lower-ranking members to want to impress their superiors, and higher-ranking members to dote on their subordinates.

There exists no strict dress code among the Middle beyond blending in with other members.[6] They tend to wear light-colored dress pants and garish shirts or coats in purple and pink tones, as well as carry around personal copies of the Book of Vengeance with them. Other common attributes include golden chains wrapped around the forearm, shins, and neck (larger amounts of chains are present on higher-ranking members), which the Middle utilize in combat, and are meant to symbolize solidarity and connection between siblings.[7] Members of the Middle are also recognizable by their enhancement tattoos; as they are allowed to get a single tattoo with each vengeance completed, the number of tattoos present on one's body tends to denote their ranking in the Syndicate.[8] In combat, they make use of punches and kicks.

Like the other four Fingers, the Middle is a large Syndicate with a unique culture and creed that all members follow fervently. Members operate on an extremely tight-knit 'familial' structure, enjoying close fraternal ties with one another. Reflective of their bonds, everyone in the Middle refers to each other as their "Brothers", "Sisters", or "siblings".

While the Middle cherishes its own members, it takes the polar opposite approach towards outsiders. Any "sin" committed against a member of the Middle, their loved ones, or property is recorded in the "Book of Vengeance" so that the perpetrator might be punished for the deed. The Middle is well-known for never letting go of unfulfilled grudges, and members may spend years chasing down its enemies to enact justice. Besides listing the names of everyone who has slighted the Middle, the Book of Vengeance also provides guidelines for the punishment to every conceivable crime, which range from killing a sibling to the simple act of stepping on a member's shoe.[2] Depending on the crime, the Middle will not hesitate to annihilate everyone in the perpetrator's faction, town, or social circle. As with the case at Rodya's hometown, the Middle may not even care who actually committed the sin, and will just opt to enact mass vengeance against whoever's in the vicinity in order to teach everyone nearby a lesson.[3] On the other hand, slights between members of the Middle are generally ignored and forgiven.[4] However, joining the Middle isn't a perfect solution either, as members are forbidden from leaving. Anyone who attempts to move on from the Syndicate will be hunted down by their former siblings until they die or erase absolutely every indicator of the Middle from themselves.[5]

Typical of those in his primary faction, Matthias is deeply devout to those on his side and brutal to those not. He is shown to feature an intense excitement at the possibility of reuniting with Ryōshū, who he called "buddy" in her youth. He features a toy-loving attitude, which contributes to a short attention span likened to hits destruction of new toys, as well as a tendency to buy and collect things he has no intention to actually use. Despite this somewhat immature personality, he remains highly capable in combat, able to fend off a variety of opponents at a time, with a litany of specific tools that assist his battles. Even with his boisterous personality, Matthias is a brutal and dedicated man who understands the goal of his side, never wavering when it is threatened or questioned.

However, at his core, Matthias is an intensely selfish man who only truly cares about short-term pleasure and indulging his hedonism. While he expresses affection for those under his watch, his understanding of parental care is highly superficial and neglectful, mostly involving flaunting his wealth and spoiling his "children" with no heed for consequences. Ultimately, he treats the needs of his peers as entirely irrelevant compared to his own, even fellow Middle members, and will even sacrifice them in a heartbeat if it benefits him.

Matthias is a bulky man, with dark skin and pure-white hair worn short with blunt bangs. He is typically seen wearing a pair of thick sunglasses, with a gold bridge between the lenses. He wears a white suit overtop a black dress shirt — unbuttoned and revealing a large scar on his chest — with a massive coat with the colors and pattern customary of members of the Middle worn over his shoulders. He keeps his Book of Vengeance on his left hip, with his opposite leg wrapped in golden chains. Notably, his right leg appears to shift through the use of his enhancement tattoos into a large claw, one he uses in combat. He is missing his right arm, though is shown to have worn white gloves on both hands in the past. His body is covered in enhancement tattoos, similar in design to other members of the Middle. On his back rests an oversized metallic sword and scabbard.

The sword, Lævateinn, is bound by at least three layers of seals, taking the form of thick chains keeping each layer tightly bound. When revealed, the sword appears with a thin-tipped appearance and a red burning hue across the entire length of the blade.

Ricardo is an extremely confident and imperious man, especially in combat, who is self-assured in his abilities with his imposing title to the Sinners as a Big Brother of the Middle. He refers to the world as binary, a part where one is luscious and one is bristly, similar to the texture of hair. Ironically, Ricardo is incredibly protective and almost obsessive about the quality and shape of his hair, with the Book of Vengeance even stating that the 'sin' of stealing hair salon coupons results in complete extermination of said 'sinner' and their other affiliates.

Ricardo is also quick to point out any 'sins' an individual has committed, as shown when Ricardo appoints Heathcliff's sin in the Book of Vengeance for lack of respect for varying tastes when Heathcliff addresses the colorful kitty stickers on his personal safe. Ricardo seems to speak in a rather archaic and foreboding tone when addressing a 'sin' within the Book of Vengeance.

Ricardo, despite his intimidating appearance, loves cute things, like kitty stickers and cute boys.

Ricardo is a tall man with a muscular build, with red eyes usually hidden behind his black tinted sunglasses. His hair is hot pink and combed back, with multiple intricate tattoos on his torso and face, which glow purple when using his power as a Big Brother. He wears a superfluous amount of shiny golden chains around his neck, arms, and shins. He wears a large purple fur lined coat around his shoulders with a leopard pattern, along with white dress pants with purple leopard-patterned dress shoes. His belt is adorned with gold along with the logo of the Middle in the center, with a golden chain holding a bulky copy of the Book of Vengeance.