Being more specific about what type of weapon or plugin you want would be helpful. The website you linked has 5,815 words. Also, are you using TF2Items on your server? TF2Attributes?
If you are looking to make just custom weapons you might try the '[TF2] Custom Weapons 3' plugin written by Theray070696. Note: I haven't used it but here is a link: https://forums.alliedmods.net/showthread.php?t=285258
If you want to make a plugin that changes you into an MvM Boss and gives you custom weapons you might try the 'Be The Deflector Heavy' plugin by the talented Pelipoika. I have used code from this plugin to make many of my own bosses. Here's a link: https://forums.alliedmods.net/showthread.php?p=2179796
Here's a video showing some of the Bosses on my server: