The green stuff looks good and the pose is proper for a mighty black templar
I like all the details on his chest and this little shield- great place for some freehand.
As for the nunchaku I think it's more a medieval flail based weapon and matches well with BT fluff.
to make a good and straight tabbard, i have a method
shape in a block of school clays the form of tabard, the general form plus the shape, and put the clay in the freezer for one hour
then you will have a support to make the gs straight and with realistic shape
after you just have to wait to make the gs hard, and bring the right done tabard to glue it on your mini
sorry for the strange explanation....my english is so bad