The simplest Krystal Papercraft has an Adventures version, free for download from Zienaxd's gallery.
A Krystal kigurumi-style cosplay that's been in development slowly since 2015 or so. First appearing at Madrid Games Week in 2018, there might have been another appearance just days ago.
An Assault Krystal pepakura available for download.
Project hasn't been updated since January 2013.
A somewhat easier Krystal papercraft project.
This Smash Bros Trophy Krystal Papercraft can be yours with the downloadable PDO file and lots of elbow grease.
Krystal papercraft shows up, this time at life size scales.