Also you will have to make a new npc with new files (can mimic a npc but rename everything) if you want, because you have to add the effect to the shader file (sht)
Example: Take human male and add hologram effect to the shader. It will change any character/npc that has the human male shader (aka all human males) to have that same effect), so your best bet is adding making a new set of files.
Ok so: adding it to humanoids probably won't work right with how Sony did faces. It doesn't look correct. I will add a pic. Now creatures it should work fine, but ye. Here is human male.
get on irc and talk there if you can. Way easier to discuss it.
Word. I'm pretty sure creatures are fairly easy. Humanoids are lengthy (very) especially with clothing, but the face acts weird since it is a separate entity.