Thread:StanFord85/@comment-25983501-20200704075152

Someone had released Slender Fortress Modified for public/open source:

https://youtu.be/BW6Hy2Q9qtQ

https://github.com/Mentrillum/Slender-Fortress-Modified-Versions

https://forums.alliedmods.net/showthread.php?t=325345

(I hope you'll likely have an experience on modeling and/or SF2 boss creations.) 