Hi

The red would work well as would maybe some yellow and red in the plumage. Maybe also a bit more contrast shading.

As to ‘finished’ how far and how big do you want to go?

You could have a couple of swords or spears crossed behind the spinal column.

The whole tattoo could be embossed onto a shield as a motif by itself or as part of a larger design.

Could have a serpent snaking around the spine.

Piles of bones or broken weapons in the background.

The only limit is imagination and skill of the artist.

Take care
Matthew

Yeah its missng a body. Zingggggg.