Well, I've spent about nearly 5 hours trying to figure this damn thing out. I play some files in my MPQ, they are named to directly replace the Daggoth Portrait. In, "Portrait\udagg\udgfid00.smk" and so on with the replacing portrait files. However, it does NOT REPLACE IT AT ALL. It instead continues to keep the original Daggoth portrait, even though it technically shouldn't exist anymore because it has been replaced.

So I tried just putting the portrait in a new folder, not replacing it, and then switching out what the Daggoth Portrait file is actually using with this instead. Still no luck.

(I actually got one more idea after this, but it probably wont work so please tell me if you have any ideas.)

Make a new .mpq, import your files to portrait\udagg\, and see if it works. If it doesn't, SC is not reading your portraits because they're incorrectly made. If it does, then something's wrong with your base mod in the other .mpq.