Today we tested out our vertical cuts on various sizes of newspapers roll. All the students learned the specific cut just before testing it. So they didn't have much time to master it.

http://www.youtube.com/watch?v=MYV7O3lvWes
My try on 4.25" roll with Deva Slayer.

http://www.youtube.com/watch?v=98IhAQ_vOW4
My student Man Kit's successful run on 2.75" with miao dao.

http://www.youtube.com/watch?v=-V_aKOKEGFo
Ho Man's failed run on 3.25" with miao dao, finished by Man Kit.

http://www.youtube.com/watch?v=hRi0lUqZ398
http://www.youtube.com/watch?v=597GwbSiCXk
The other students tested their skills at night. There were lighting provided by a friend later on so the video was more "viewable" after 1:18.

that deva slayer really is an impressive weapon.
what age and area does it come from (the originals) ?

It was a Chinese design from an era long lost in age. I'm not sure about exactly what age it was from. The design was given to me by my master.

Gottfried P. Doerler wrote:

that deva slayer really is an impressive weapon. what age and area does it come from (the originals) ?

One thing that springs to mind is that unless fighting goblins, few vertical cuts are aimed at a waist height target. Maybe a shoulder or head height one would be more relevant?

The student who started the vertical cut practice trend, "Cloud", broke his own record by cutting a 5.5" roll with the final version of the vertical cut.
http://www.youtube.com/watch?v=mRiKhnkcxXQ