From MC's perspective:
Time flies,
After several hours of journey, the fortified train reaches the border of the Capital City. There is vast green land before the border.
But I don't know why a bad premonition hits my heart. When I looked at other passengers. They are enjoying the passing view through the window.
I'm the only one who is having this uncomfortable feeling. Then I stood up from my seat and went to the washroom.
As I walked past a few seats, I noticed a black liquid covering the train windows. Seeing that my expression changes drastically.
This reminds me of the unique spell attack of an unknown level-7 wizard.
Outside,
Black liquids are appearing on the train track. When the train passes through it. These black liquids then enter the wheel and later the compartment.
Not far away, the triple killer is manipulating the black liquid. In the blink of an eye, most of the compartment was under his control.