Summary

This is a pen in the shape of the master sword from the Legend of Zelda video games.
Print the file twice and glue them together. You can take the pen tip and ink cartridge from a bic pen and insert it after gluing the pieces together or place it in between them before gluing them together. I had some trouble putting it in after so it's probably easier to do it beforehand.

The last two pictures show how when I printed it, the two pieces didn't fit together great, there's some gaps. I'll probably reprint it sometime to see if I can make them fit better.

I thought of, designed and printed this idea on my own. Afterwards, I looked for similar designs on thingiverse out of interest. That's when I found WildRoseBuilds sword pen.
https://www.thingiverse.com/thing:2536783
It's a total coincidence that I used the same method as they did for this print. So it's technically a remix of their design.