Yay more for good old Yoshi mod! Since I've noticed all official Yoshimitsu's costumes have different colors for sword slashing effect (Green in C1, teal in C2 and purple in C3), I thought there should be a way to change the color of it. That, and then we're good to go to... I don't know, a Darth Vader mod? I'm not saying you should make it, just giving out my thoughts.
its not really voice modding but all i did to replace voices i didnt like for mods was find a sfxt character voice i did like that fit the mod, like for example swapping yoshimitsu's voice for hwo's english voice since it fits deadpool. just find hworangs(sp) english voice files and make two coppies. rename them YOS instead of HWO. the deafault for yos is japanese for some reason, youll notice on some of them there are "e" or "j" letters this is where the 2 copies of the english HWO voice comes in. on one set of english voice files, change the "E" to a "j". after you are done renaming all the HWO files to YOS and changing the "E" to "J" on that one set of english files, just coppy and paste to Yoshimitsu's sound file and bingo! a better deadpool voice. hope its not too complicated, im not good at small tutorials.