I actually learned of the Mousou Voice line readings a month or so before the posting here, but I always had a Left 4 Dead mod in mind since the instant I heard the sample. Watch this clip and be amazed at how I spectacularly miss the point of the tsundere archetype.

I selected the lines without noting that Witch sounds often don't play completely, especially the ones that signal her attack. Some sounds are left unchanged, most likely because they were too short. Additionally, you might not be able to hear some lines over the music. This mod should work with both games as they use the same file names. Left 4 Dead 1 should ignore the extra files.

Note that this video is in no way indicative of my skill in the game proper. This is a work in progress and I worked all night on it, but I'm not willing to put it out yet. If anyone can tell me what scripts to modify in Left 4 Dead 2 so I can get more lines in, please let me know. It feels like a waste otherwise.