False Berserker

Berserker (バーサーカー) is the Berserker-class Servant summoned by the Flat Escardos in the False Holy Grail War of Fate/strange fake.

Identity
Berserker True Name is Jack the Ripper, but lacks a true identity, instead acting as the embodiment of the mystery behind the legend of Jack the Ripper in the form of an "emblem of madness." Brought forth by a toy knife from Night Wars of the British Empire, he is not the soul of an actual person, and he only knows he is "Jack the Ripper" and has no knowledge about the true identity behind his legend. He claims that only the true him, rather than the him of legend, or someone who put a stop to his murders would know his true name. This aberration is due to the fact that he is summoned with an imitation of a real relic, but it did draw a much more powerful spirit because it was an imitation designed for public use.

It is known that Jack the Ripper existed without a doubt due to the five corpses of prostitutes found in the Whitechapel district of London. There is no name associated with it other than that which was written in the letters, Jack the Ripper, but it is certain that he had to exist in some form. There is no physical description, associated gender, true name, or even the certainty that he was a single person or even human. This makes him a being with an appearance and manner of all varieties, while at the same time having none at all.

He became a symbol of fear that terrified the world, causing people to imagine him in countless ways. The legend became a topic of many tales and theories, including him being a doctor, teacher, aristocrat, prostitute, butcher, devil, faerie, some sort of conspiracy, or even just madness. People's fear was exploited to create many different stories about him that became united into a single legend. Even in modern times, he is among the most popular of legends in England.

There is another incarnation of Jack the Ripper that can be summoned, and though that version also qualifies for the Berserker class, it is suggested that version is summoned under the Assassin class, while this version is summoned under the Berserker class.

Personality
Berserker speaks in a friendly, refined, and polite manner with a crisp tone unbeffiting a mad warrior due to the unique circumstances behind his existence. He is constantly surprised by Flat's ineptitude and lack of decorum, but handles it in a calm manner.

His reason for seeking the Holy Grail is to learn of his identity. He is only a fable without presence, but the idea of people inventing stories and hypotheses about his true identity frightens him. He is without a body, name, or past to call his own, so he wishes to know himself. He knows that he was a serial killer no matter his current form, so he must be as true to reality as possible in order to match the person who existed. It is a strange wish, but it is likely the only thing he desires.

Fate/strange fake
Berserker is summoned by Flat Escardos during broad daylight in an inadvertent manner, surprising Flat with the question to complete their contract. He is amazed by his Master's ability in performing the ritual without a magic circle or incantation. Flat is confused by his identity, having used what he believed to be one of Jack the Ripper's knives as the catalyst, due to it not matching his preconceived idea of a Heroic Spirit. Berserker displays his nature by becoming a police officer and accosting Flat for his suspicious nature. He reveals himself to the flustered Flat, transforms into a woman, and then returns to his spiritual form.

He explains his nature in that he does not know his true self and the contradiction behind his personality and class. He then asks Flat about his reason for not handling the supposed police officer in a way that required only the most basic of magecraft because he is worried about his Master's competence, but Flat simply downplays it in embarrassment. Flat questions him about his wish, which he embarrassedly admits is finding his identity. Flat blatantly says that there should be no real Jack the Ripper, shocking Berserker. He then ruminates on Flat's choice of a serial killer who is neither a hero or someone of morality, but is once again shocked by Flat's bluntness.

His Master should be hesitant of even being in the presence of one such as him, let alone deciding to summon him, but Flat simply finds the mystery behind the legend to be interesting without any other thought behind the choice. He then prepares himself for the upcoming conflicts with optimism and high spirits, wishing to plan a course of action. Flat once again shocks him by wishing to enjoy the weather, and they later leave the park after avoiding one of the Police Chief's agents. He has the potential to ally with the Player, but he many not be as trustworthy as he seems.

Abilities
Berserker is a unique Servant lacking a regular form, only communicating with his Master through telepathy. Flat is able to feel the energy flowing through the Command Spells to an unknown location. It is a voice lacking any sort of unique characteristics, making it impossible to distinguish gender, age, or any traits about occupation normally given away by details in the voice. Due to the identity of Jack the Ripper having never been discovered, he is "nobody", so he is able to transform into a myriad of different people with the ability to "become anybody." He is able to instantly manifest out of view, quickly change form while someone is distracted, and stopping the ability causes him to instantly disappear and return to his insubstantial form. He also takes the form of a watch that Flat wears during the day.

The ability is one that allows him to infiltrate anywhere he pleases to kill Masters in close quarters. He can manifest tools associated with the identity, such as a police officer's baton, and they will fade away instantly upon changing identities. He can act the part of an angry officer or a feminine woman in a lascivious dress, though his voice still carries some of the same neutrality as his regular voice. He also possesses the ability to possess his Master, and retaining his madness under any other Class, he likely would have possessed Flat and slaughtered everyone within the area in a maddened rampage.

The reason for his calmness in the normally maddened Berserker class is unknown, and he explains that having been enshrined in legend as a symbol of madness, it is the only class that truly fits him. This causes Flat to speculate that a "negative times a negative makes a positive" in a manner unbefitting a normal person. Berserker believes it lies with his nature of not actually being the soul of the real Jack the Ripper. As a symbol of madness, he thinks he was overlooked in a way that would not have happened if he had been the soul of an actual person. He does not know if it is a miracle or a unique part of the flawed ritual.

Development
Due to Berserker's unique nature, Narita contemplated how he could be implemented into Fate/Grand Order if he were to be added, wondering if he would be something like an invisible man or a floating watch.