here is closer (means more detailed) concept for that archangel from my last artwork "One failed Uplift" . You already knows the reference for this concept was a swan ... if you think that stupid idea ,maybe that will help you: angel -> wings->swan wings-> swan simple and logic isn't it, however I must admit the final concept has nothing to do with cute little birdy and it looks even more twisted here then on previos illustrations. Still -I hope You like it

 

here is actually reference for archangel-alien

http://ptaki.polska.pl/gal/85/15/93/med.jpg