Head: Resolute Storm Shadow
Neck post: 25A Destro (Iron Grenadiers uniform) cast
Chest/back, waist, gi skirt: NS Tiger Claw
Arms, legs: '04 Slice
Sword, sheath: 25A Hard Master

Design:

Gold Ninja Assassin was a mini-figure in the Micro Force line. It was unclear with which team, if any, the character was affiliated, so I see him as a freelance operative. The parts are mostly NS ninja goodness, plus the nicely sculpted ME Storm Shadow head to improve the overall appearance. Unlike most NS figures, the proportions on these parts are pretty good.

Colors & Paint:

Based on the Micro Force figure. The MF figure has a dull bronze finish. To mimic it, while making it have a bit more luster, the custom figure is brown with a metallic gold wash applied.

Sculpting & Modifying:

The neck post is cast.

Thanks for looking.