Well, you do seem to have mostly cels of Sonia 
and she's the one I have the *least* trouble with 
where line fading is concerned. (The lines in the 
blue colors seem to hold up better.)

The places I'm seeing the most trouble with line 
fading are Keith's hair/gloves (white), Wong's 
coat (the white/yellows/reds), and Burn's hair 
and jacket (yellows/reds again). One of the cels 
I just got of Wendy has severe line fading in the 
hair (pink), but the other two I have are just 
fine -- I have so few cels of her, I can't really 
make a good judgement call on that. . .

So if you're a Sonia fan, you're safe. ^_^

(And in case it wasn't obvious, I collect from 
the show because I'm an insanely pathetic fangirl 
for the story. ^_~~)

Many Sharp Smiles,
--Drac