gets knocked off the train, skills himself back on

Kamijou had been blown toward the back of the train by an artificial blast of wind and the
giant boar Hildisvíni had tried to charge at him. However, he had grabbed at the coat of
his school uniform.
Even if he flailed his arms and legs around while in midair, he could not move as if
swimming through water.
But what if he had something that could fan the air even more?
What if he unbuttoned his coat and spread it out?
“!”
Kamijou intentionally opened up only the right side. He had no guarantee it would work.
It was a complete gamble. As soon as he did, his body moved as if being greatly twisted.
The gust of wind was powerful enough to easily blast a human into the air, so it was
obvious what would happen if he prepared a makeshift sail that increased the air
resistance.
As his body spun, he was pushed to the side.
And he fell.
As the giant boar scraped along the top of the tunnel, it ran directly along the roof of the
train. By that time, Kamijou had already avoided it by grabbing onto the edge of the roof
with both hands and pressing against the wall. Hildisvíni was large enough to fill the
empty space, but that was only the area above the roof of the train. The gap next to the
train’s wall was wide open. The wind produced by its giant form did not reach down there
either.

- New Testament Volume 8 Chapter 4 Part 11