The base template for MNOG style characters (mostly matoran, but there are toa sprites for toa Mata and Nuva) exists but it does require some image manipulation. (Nothing more complex than cut and past and changing colors, though.)

And yeah, I was imagining a bit more Metru-Nui esque architecture which I thought powerlines of some sort would fit into. Underground ones are cool too though. The main thought process behind it was it could allow for interesting action sequences, possibly evoking the feeling of the chases in the chutes that the Toa Metru went through.