i believe the tears were both fred's and illyria's. illyria had some of fred inside her--she said in "shells" "there are flashes. memories"--and she knew that that's what fred would have done during a time like that, but i think she also felt for wesley, and was confused and troubled and at times overtaken by human emotion that she didn't understand. i think she started to cry as fred, and then cried as illyria, too. i'm not sure why, but wesley and illyria/fred's relationship and how it ended/how wesley died was perhaps as heartbreaking and beautiful for me as buffy/spike in "chosen," buffy/angel in "becoming," anya/xander, willow/oz, and willow/tara. wesley really grew on me as a character, and i think i can say he is in my top five favourites out of all of buffy and angel. i thought that the illyria/wesley dynamic was amazing and the episode "shells," particularly the last ten minutes or so, is beautiful.