Custom voice lines are... a bit of work. Here's a tutorial i tried to follow when making my onw voiced characters (as part of Flyguider & co Mod)
https://www.youtube.com/watch?v=jZmRc4vbZxQ

Hope it helps :)

Hey, thanks so much for this! It's a massive help!

If it's all the same to you, could you also give me a tip to a good way to make character portraits?

Hi. To be honest, I have used the following AI for my characters:

https://perchance.org/ai-text-to-image-generator

I used the option "digital painting" but other options may also yield results that fit your idea of the mod.

Been trying to troubleshoot it, I followed your instructions but the voicelines don't play anything, not in game and not when I press the Play button in the Mod edit page. Any suggestions?

Hm... I probably had the same issue at some point but I did this quite a while ago and don't really recall what the issue was and how to fix it. The tutorial video is not from me. So I don't really know any more than what I can look up in there I'm afraid. It's really needlessly complicated.

It should work if you followed the Instruction to the latter, so the most important part is to get the ID thing right. The sound file has to match the ID from the .csv file as shown in the video. But i have to agree with Papi, this is far more complicated as it needs to be...Also install the Commonlib Mod when working with the editor. To Quote Dr. Q: I have diagnosed a problem with the editor you have given me....It is ♥♥♥♥!

I did, maybe the issue was I took a shortcut, and instead of making copies of each voiceline, I just renamed the voiceline as such.

Also, some of the csv ids were identical. Like, I have 3 enemy spotted responses, and apparently thats too many? Because both "Enemy Spotted" and "Theres an Enemy There" voice ids were the exact same. I will scrap the current voice files and redo that part, see if I missed anything.

I've had good results using OtherGuy's Custom mercs as a template. Cheers to him for laying the ground work! Recommend you try that out, but keep in mind it's a lot of work! Use the mod editor to change the text to your liking, then using notepad++ open the items.lua file and find all the voice lines. Then comes the hard part which is to copy paste every single entry number and match it to the sound files for each dialogue line you've created... Lot of work there! Remember to include the voices.lua file in the mod folder! Somehow I never managed to create a voice responses from scratch as it's always missing a ton of voice cues.

Be careful adding new VRs. If '+' gets you a new line with text copied from another line, you 100% have a duplicated ID and should delete and try again. New VRs must start blank. Even knowing this, duplicate IDs pop up and need to be deleted and re-added.