Looking at this from afar, could it be that “Wet Normal” is the same or sufficiently similar to the “Marker” from Paint Tool SAI? I’ve implemented that in Krita, see this thread for an implementation, instructions and downloads for testing: Feedback Wanted: Marker Mode - #10 by Drawpile
(tl;dr instructions: the Marker mode is in the Mix category, use it with a brush that uses Build-Up painting mode for it to work like in SAI.)