There are some speedruns for Nox available at Speed Demos Archive

http://speeddemosarchive.com/Nox.html

The current fastest is the Wizard campaign done in 34m 06s by Pjoxt. There's also a Warrior campaign speedrun in 36m 29s by Onin.

Onin has also completed a Conjurer campaign run which is currently up for verification. You can find the links in the forum thread here:
https://forum.speeddemosarchive.com/post/nox_81.html