Need help with Blonde Naso - sick - looking for diagnosis

[carpe_diem]

I bought this Blonde Naso one week ago at LFS. They had unboxed him on Thursday, I got him on Friday (they had already put him in their system). I did not see him eat at the store, but he looked healthy overall. We brought him home and did a 2 1/2 minute fresh water dip on him and then put him in QT. The next day he had a noticeably grey area behind his fins on both sides (I'll post pics in comments). He has shown no signs of ich or other disease but is minimally eating at best. Grey spots have changed to this. Can anyone diagnose? Suggest treatment? He's a really beautiful fish that I am hoping we can somehow save.

 

[carpe_diem]

At Local Fish Store

 

[carpe_diem]

After dip

 

[carpe_diem]

Now

 

[zheka757]

Still alive or did it die with soars like this?

But started with sports like this