Afasys

Afasys (アファシス), alternatively spelled as ArFA-Sys in Western localisations, is an original Sword Art Online game character and the Protagonist's personal companion in Sword Art Online: Fatal Bullet. Afasys is a rare type, modeled Type-X, of an Artificial Intelligence (AI) companion called the Artificial Financial Adviser System and her full ID is Afa System Type-X A290-00. Due to Afasys only allowing the Protagonist to use Afasys's official name, the companion was nicknamed as Rei (零) by Leafa in reference to the zeros appended to her Unit ID.

Gun Gale Online
Both female (canon) and male (alternative) versions of Afasys feature white and purple prominently as their canon looks. They both have purple eyes, white hair and a skin-tight, purple-on-white suit. While the female Afasys has short and straight hair, the male Afasys variant has short and messy hair.

Personality
As a Type-X Unit, Afasys features a distinct personality, unlike the other models. Afasys is a clumsy companion who tends to make simple mistakes while handling a task, and is very forgetful in terms of remembering key information. As an AI companion, their battle personality can be adjusted by the Protagonist to suit their needs based on various parameters. While Afasys' core personality traits are predetermined, how they express themselves can also be adjusted by the Protagonist to sound bright, stoic, cute, zealous, or serious.

With the addition of the first DLC, Champion of Gunfire, situational emotes have been added as adjustable parameters that allow Protagonist to decide how Afasys reacts to certain events, such as waving when the Protagonist meets a friend, or pumping their fist up in the air upon leveling up.

Fatal Bullet
Afasys was implemented into Gun Gale Online (GGO) as part of the Gold Rush update via a special tournament. During the event, they registered the Protagonist as their master when the player touched their stasis capsule device while examining it. Having emerged from the pod, Afasys hesitantly addressed the Protagonist as their master as Kirito charged at the latter, prompting the Photon Sword Wielder to halt his attack. After the trio were joined by Kirito's ally Asuna and the Protagonist's friend Kureha, the android focused on completing their main system check and startup processes while reiterating their registration to the Protagonist when Kureha attempted to claim ownership over them, although they acknowledged the girl as their master's superior.

Once their main system startup was finished, Afasys gifted the Protagonist with an Ultimate Fiber Gun (UFG), an experimental grappling device that was relatively easy to utilize. Having taught the Protagonist how to use the UFG, the duo and Kureha were automatically transported to SBC Glocken at the tournament's conclusion, where Afasys followed their master to a party held by Kirito's friends to become better acquainted with each other.

After the party, Afasys explained to the Protagonist their purpose as an Artificial Financial Adviser System, though their related skills and stats were low-level on account of their master being a beginner player. In order to strengthen themselves, the pair joined Kureha and Kirito on a tour of SBC Glocken, learning how to use the various facilities therein to prepare themselves for their expeditions into the field. During the tour, they met several of Kirito's friends that were not present at the party, as well as a gruff gunman named Bazalt Joe who saved them from being conned by a merchant player. While doing their own exploration of the city sometime later, Afasys got separated from the Protagonist, only managing to reunite with them thanks to aid from Daisy, another Type-X ArFA-Sys Unit, and her mysterious master Zeliska.

Shortly afterwards, Afasys revealed to Kureha and the Protagonist that some of their functionalities were incomplete due to missing a few parts; recovering these components would restore the android's abilities and enable them to unlock the SBC Flügel, a new area to be implemented as part of the Gold Rush Update. Having reclaimed the first part after a quick expedition into the Remnant Wasteland, the ArFA-Sys Unit gained the ability to deposit and invest their master's credits, as well as a vague recollection of the interior of the SBC Flügel.

Not long afterwards, Afasys, Kureha, and the Protagonist were confronted by Bazalt Joe, who demanded to be given the ownership rights over the ArFA-Sys Unit. Though flattered by the man's interest in and gifts to them, the android refused to register anyone except the Protagonist as their master. Nevertheless, as Bazalt Joe would not be easily swayed, Afasys assisted Kureha and the Protagonist in defeating the gunman and his allies in two successive duels over the matter, whereupon they respectively received as a reward an expensive item and information on the location of the other missing ArFA-Sys Unit components.

A short while later, Afasys decided to take an unannounced stroll around SBC Glocken, during which they spotted a desirable piece of equipment being sold in an shop. As the ArFA-Sys Unit had neglected to inform their master of their allowance function, however, they lacked the funds to purchase the item. At the same time, the android had forgotten the way back to the Protagonist's residence, so they loitered in front of the store until they were discovered by Daisy and Zeliska, who escorted them back home. Once the situation had been resolved, Afasys apologized for not mentioning the allowance system to the Protagonist earlier before instructing their master in setting it up.

Having obtained better equipment for themself and the Protagonist with their allowance, Afasys and the others were able to follow the information they had won from Bazalt Joe deeper into the Remnant Wasteland, where they recovered the second missing ArfA-Sys Unit part. Subsequently, the android acquired a broader range of emotional reactions and the ability to switch between different outfits, as well as more memories of the SBC Flügel.

Sensing a disturbance while wandering the streets of SBC Glocken with Kureha and the Protagonist some time afterwards, Afasys followed the noise to where two players were haranguing another. Unwilling to remain an idle bystander, the android was about to intervene when Itsuki preempted them by forcing the bullies to retreat. Grateful for his intercession, the ArfA-Sys Unit and the others accepted the man's invitation to Alphard's headquarters. There, they learned what motivated their master and other players to start playing GGO, which eventually resulted in Itsuki deciding to accompany them on their adventures whenever needed, to the android's amazement.

Not long after encountering Spiegel, Sinon's friend from real life with whom she had a troubled history in Sword Art: Origin, Afasys, Kureha, and the Protagonist were advised by Zeliska on where to find the last of the missing ArFA-Sys Unit components. To that end, they defeated field bosses in the Remnant Wasteland and the Solitary Sands in order to liberate the areas and reach the Old South, though they were forced to purchase information from Argo to progress further. Having unlocked and entered a sealed dungeon in the city ruins with that knowledge, the trio retrieved the third and last part, which granted Afasys improved language processing. With their functionalities completely restored, the android helped their master with vanquishing the remaining area bosses in the region so as to reach the Forgotten Woods, where the SBC Flügel would be implemented.