Come to think about it, the Skull Villains almost work like evil counterparts to the Toa themselves, with the Skull Warriors opposing Kopaka, the Toa of Ice. The only problem is that there was no Skull Warrior of Water to oppose Gali, the Toa of Water. SkyBird made a pretty interesting Skull Villain MOC called the Skull Shaman, which notably sports some custom-dyed bones in translucent dark blue, as well as a fun play feature that waves the Skull Shaman's arms around like he's performing a necromancy spell. Having the Skull Shaman be the Skull Warrior of Water really does help flesh out the Skull Villain pirate crew, and sell the idea that these guys are like anti-Toa in the same way that G1 villains such as the Bohrok, Piraka, or Barraki were.
