please critique this design

[CajunDave]

outer arm from ditch to top of shoulder so its gonna be big.

the smoke from the top of the train is gonna cover up a shitty skull. im thinking of kicking the flames and keeping the blue as a background pop color. im gonna leave more space between the wings and the train and im gonna reverse the dark shading on the wings going from the outer tips instead. i only have the cool grey markers but when i tattoo this im gonna use cool greys on the wings in lighter shades and use dark warm greys on the actual train to help the seperation. eyes on the wings are to badass looking for me to drop it im thinking of making them less intense though color wise and save the color for the eye in on the nose of the train. the eyes on the wings are gonna wrap a bit around his arm so should be a major focal point when viewing the tattoo head-on.