This is kind of a weird one. I have no idea what a Beast Ninja Soldier is. This figure comes from the 2013 G.I.Joe Micro Force line which featured many familiar faces and also some total mystery characters like this.
I'm not even sure he's Cobra. That's just a guess.
For Beast Ninja Soldier, I used a Heroclix Wolverine with green stuff for the mask. Unlike other miniatures I've done, I didn't repaint Wolverine's eyes. They looked pretty crazy as it was, which seems to fit the "beast" part of the name.
Actually, Beast Ninja Soldier is a pretty good description of Wolverine, isn't it?