This stars set has got to be fairly big I would hope and not just here's a few bits and pieces out of a 5 bionicle set.
If we look at what's shown already we have.
We see a main mask (as sene on tahu)
3 identical pieces. Likely one for each arm armor and one for the chest armor (as seen on tahu)
The gold (not sure what it is) looks like sword hilt as seen on skrall but used on tahu.
The gold piece which was a hand part from set I don't recall I know you all do as shown with the rashiki. Where it will go is not shown yet. but I wager to be utilized as a shield.
So based on those pieces.
Missing parts..
head for mask to attach to
arm x 2
hands x 2
body x 1
leg x 2
and weapon x 1
feet x 2
This would leave the set open for 10 more bionicles, plus one for the head piece (likely no head piece I'd wager).
This would be pretty cool a set of 15 stars and the instructions on what head to use and additional parts from your sets to build the golden bionicle.
But this just what I see it's probably nothing as grand but we could hope.
More than likey based on this picture (not sure where it came from other than bzp).
Those 5 pieces they show are all the parts you need to make Tahu.
Gold arm armor
additional chest amror
weapon bottom guard
gold mask and
right hand shield.

Kind of disappointing IMHO for a golden bionicle.