hi foul soul i want to help u the way to pk2 edit avatars in swsro is to download the swsro pk2 files and pk2 edit the angel wing.bsr (in the data.pk2)
avatar_m_angel_wing_dress.bsr to be exact. and switch it to another avatar make sur to change the new avatar"s file name to avatar_m_angel_wing_dress.bsr and then import the new file. (the one u changed it's name)and here you go the impossiple pk2.
if u want the devil spirit avatar u will get it without the wings or get the wings only u make ur mind.
if u have troubles doing it i can do it for u or make a tut so every body can.
note:i dont like the guide thing but will see if u need it.