>>7194682the kit is great for nova prime, though the shoulder guards/windvane pop off easily due to design.
it's a bit troublesome to get the pins out, but all you really need are extra hands or a clamp and a hammer, the kit provides the rest of the needed parts.
might need to shave down some bits though, molding inconsistencies.
as for combined form, he looks cool, but the combiner is unstable and kinda difficult to pose much leg wise, too much is in the way of the legs to move, and then he's too heavy to hold poses.
also, the bigger head is a simple helmet that clamps onto his nova head.
the kit is a little fiddly, but if you like the look, and have a white prime mold around, he does make the figure feel complete, just, don't plan on him being a combiner, he's not that cool.