Part 1 - What is X.Y.B.E.R. Grand Prix

In the last 60 years of the X.Y.B.E.R. Grand Prix, There was always a participant who endures survival within the race.
Some say he is a myth.
Others say he is just a urban legend.
But on the 46th X.Y.B.E.R. Grand Prix, he once again appears...
The Participant known as -Skull(頭骨)-