The lost soul

It's April, and we all know what that means. It's time for the ultimate prank to be thrown on the least lucky person. Our squad picks a person the most suitable for the victim every year, but this year is special; It's our last year here, and we gotta make it memorable.
We choose. But this time, she chose us, the reasons unknown till it's too late.
The prank we played on her did not go according to plan and we least expected the almost forgotten legend to actually be true, and to come bite us in our asses;
The legend of the lost soul.......