libc6 dependency mismatch

I've created a Frankenstein's monster by adding Kali stuff to my source list like mentioned in this guide: https://medium.com/@sany4sec/how-to-install-kali-linux-tools-in-ubuntu-or-linux-mint-b2ce8453964e

That worked "fine" but I now get the following error when running apt upgrade:

The following packages have unmet dependencies:

libc-bin : Depends: libc6 (< 2.36) but 2.37-12 is installed

libc6-dev : Depends: libc6 (= 2.35-0ubuntu3.6) but 2.37-12 is installed

         Depends: libc-dev-bin (= 2.35-0ubuntu3.6)

libc6-dev-i386 : Depends: libc6-i386 (= 2.35-0ubuntu3.6) but 2.37-12 is installed

libc6-dev-x32 : Depends: libc6-dev-i386 (= 2.37-12) but 2.35-0ubuntu3.6 is installed

             Depends: libc6-dev (= 2.37-12) but 2.35-0ubuntu3.6 is installed

locales : Depends: libc-bin (> 2.37)

I have disabled the Kali stuff in source.list and tried sudo apt update, sudo apt upgrade but the error persists. Basically, I can't upgrade anything and would like to revert this. How can I rid my system of anything 2.37.-12?

Just to confirm, sudo apt --fix-broken install does NOT work in this case. Help please...I promise I will never try to create a Frankenstein again! :/