duff did a cake similar to this.... i think it was the sutton hoo cake.
I guess it depends on how big yo need it. You could use the round ball pan on top of a few 6", or make layers of cake and then carve (which would waste quite a bit of cake).
I would use fondant for the outside armor (sp?) and would consider real feathers for the top inserted into coffee stirrers.
Oh, and lots of support dowels.
this may help...
use ovals for the bottom 3 layers and then a half round ball for the top.
you may need to have more than 3 layers -- as many as 5 even and use the soccer ball pan for the top to get it as big and as proportional as you need.
then its just a matter of cutting away to get the say as indicated by the gray areas.
notice also how you have to cut back the end of the oval as you go up the stack to match how the face curves.
the diagram reads left (bottom layer) to right (top ball pan)