Fate/Champion The Irregular Servant
Illyasviel von Einzbern prepared her summoning expecting the strongest hero: Heracles.
But the circle failed.
Instead of the Berserker who was supposed to crush the Holy Grail War, a different Servant appeared before her.
Reiya.
An impossible Servant occupying the Berserker slot, yet registered by the Grail with a Class that should not exist:
Champion.
An impossible title for a hero with no legend in this world.
Reiya was not a king, a demigod, or a figure written in myth. He was a mortal who, in another world, achieved something no mortal should have been able to achieve.
What exactly did he do?
Even Illya does not know.
All he has is a broken sword, a past filled with war, and one bad habit: stepping in front when someone is about to die.
Now, in a Holy Grail War that is starting to break away from its own rules, Illya and Reiya must face legendary Servants, hidden Masters, and truths the system was never meant to allow.
Because Champion is not a normal Class.
It is proof that even a mortal can rise against powers above heroes and gods.