Holy Grail War.
About once every sixty years, the spiritual energy in Fuyuki City's ley lines will accumulate enough power to support the birth of the Holy Grail, and then the Holy Grail, which has the power to instantly realize any wish, will appear in Fuyuki City.
However, only one group of magician masters and servants can obtain this right. To compete for this right, seven groups of forces fight each other until the last group is left.
But at some point, magicians were no longer satisfied with driving heroic spirits to fight. The inability to completely control the noble heroes in history or mythology made magicians restless. Some heroes even ignored the master's instructions and acted as they pleased. The three Command Seals are like nothing.
Until one day, a young magician proposed to sign a contract with the summoned heroic spirit. He would use himself as a body, borrow the power of the heroic spirit, and transform himself into a heroic spirit to participate in the Holy Grail War. The winner and the heroic spirit would share the rights of the Holy Grail. This seemingly innocent idea unexpectedly gained support from many magicians, and this young magician was able to devote himself to the research of "self-heroic transformation" with the support of many human and financial resources. After many experiments, sixty years ago, during the last Holy Grail War, "self-heroic transformation" was basically realized.
Saber.
Archer.
Rider.
Lancer.
Caster.
Assassin.
Berserker.
Seven magicians.
Seven heroes who participated in the war.