Some of these are not open source but he is okay with sharing them and you can see the code with dnspy, they are not obfuscated.
https://github.com/CodeCracker-Tools
https://github.com/CodeCrackerSND
https://gitlab.com/CodeCracker

and here is a list of a lot .Net Tools for reverse engineering
https://github.com/NotPrab/.NET-Deobfuscator

I also have more tools on my repo which can be found here, however I don't have the source code : https://github.com/InstinctEx/deobfuscatetools/
I'm not asking for every single bit of those tools to get added but some of them are really useful.
Making this issue so you can check them out.