Here is a set combiner of Mask maker vs. Skull Grinder and Skull Scorpio (sets 70794 and 70795) or as I like to call him, Ultimate Kulta.
It's a really cool combo, IMO.
You can find and download the instructions on the Lego Bionicle website.
Notice: If you want to build the combiner set as it shows in the instructions you will need 5 extra pieces: 2 red pins, 2 of those half thick (3 piece long with two axial holes outside one round pin-hole) pieces, and 1 t-piece I don't know the names, please stop my suffering...
Here is a picture of them.
Here are some pictures I took of the combiner I built.
What do you think of this Combiner?