Assassin (Fate/Extra)

Assassin is the Servant of Julius Bistari in Fate/Extra. He later becomes a Berserker after avoiding deletion.

A Second Strike is Needless
In the history of Chinese martial arts, this was the second name confered to a martial artist famous as one of the strongest. The martial artist awarded with this title was a master of Bājíquán said to snatch away the life of his opponents during matches just by touching them, no matter how light of a touch.

Presence Isolation
A Skill to take action while concealing one's figure.

The ultimate form of becoming transparent, but because great amounts of prana is used, it ends up leaving signs that "Magecraft is being used". Therefore, in cases that the opponent is an excellent magus, the fact that "someone whose figure cannot be seen is at work" ends up being perceived.

A capacity to become transparent that does not rely on Magecraft and is performed only with one's own body techniques. This is already a mystic art that can no longer be designated as in the "level of humans".

Background
Li Shuwen. 1864~1934.

A Chinese martial artist from Yanshan County, Hebei - Cangzhou. A prominent martial artist in the history of Chinese martial arts, renowned as "a second strike is needless, so long there is one it will suffice".

The progenitor of the Li clan's branch of Bājí, Li Shuwen excelled in the use of spear to the point of being nicknamed "Divine Spear Li". The "Six Harmony Great Spear" that he used was a basic weapon of the Bājí-branch and, if one is to accept this extreme logic, it can be said that the unarmed techniques of the Bājí-branch (the Bājíquán) are nothing but preliminary steps to learn the techniques of this great spear. Originally his Class was supposed to be Lancer, but in this case he would appear with the figure of his late years. It is thought that he appeared as Assassin due to his Master, Julius, desired a young and ferocious Li Shuwen out of compatibility.

Also, this is a digression, but his capacity to become transparent is an essential point of meditation in accordance with Sphere Boundary. Because it is a capacity to become transparent that does not use any Magecraft, for those who live under thaumaturgical theories this is a technique of experts that "absolutely cannot be sensed".

...An additional digression, it seems there was once a swordsman who, similar to Li Shuwen, could use just human techniques to freely create split selves, without using any Magecraft. The name of this secret sword was Tsubame Gaeshi. Oddly enough, it was a mystic art from the Assassin Class.

Demon Fist Master
Demon Fist Master, Li Shuwen.

A master of martial arts who fundamentally keeps the morality of the innate goodness of man, but at same time also accepts evil. Said to have brought much hatred due killing too many opponents and finally had his life ended by being served poison.

As a Servant, Shuwen's morality had deviated from the general common sense, but his humanity itself is that of a "sensible person" that esteems rationality.

Does not see great difference in justice in justice and evil, but if someone's behavior offends his rationality...like with much futility..., blunt disgust will be pointed towards that someone. In cases when that someone is a scoundrel that lust for profits, and there are pleas by those damaged by that someone, under the terms of "a connection has been made", Li Shuwen will confront that someone and commit murder as a result.

At a first glance this would seems as an act of chivalry, but since the chivalry of China is "pick up a sword out of passion", his way of thinking is the exact opposite. Rather than rational, Li Shuwen's character is something better described as being close to that of modern people.

Li Shuwen was someone who simply (not purely) sought for strength, but it has been said that, in his late years, he discovered the valor of the strength of conviction, one's way of life, instead the strength of violence.

He acknowledges that he is a kind of professional killer rather than a martial artist, but that is neither a self-depreciation nor a boast. Given that he often learned, often fought and often murdered in his previous life, he really does not carry any regrets or grudges. Since he was summoned as a Servant, he swings his wicked fists as the concealed weapons of his master Julius without hesitation, but....?