I'm not entering, but I'm giving some advice of things I'll be looking for.

1. mask; don't use a stand alone mask unless you use Kongu Inika's, it looks good enough alone. If you don't know how to make a good mask, take one that looks good and flat, maybe a Hau, then put some pieces, maybe another mask over the top and attach with a rubber band.

2. chains; Maxilos, Jaller Mahri and Vezon can be used and just make a long one.

3. armor; since he can rebuild himself, use any color really, though black and gold/yellow are best.

4. matoran; two custom matoran, can be damaged, like the crazy Av-Matoran, or can be enhanced, like the Voya-Toran.

That's all I have, I'll edit this with more if I think of anything.

Edit: If anyone has any other suggestions, post it in the discussion of this entry.