O’Shaserra or 'Shadowsun' (or even Shas'O T'au Shaserra), Supreme Commander of the T'au army, ready to serve the Tau'va !
(This version was made by the artist @ryuusei (mark ii) )

You can find reference below :

NOTE : If there are any defects, don't hesitate to let me know so I can try to resolve them.

ART : @ryuusei_(mark ii)