Mercury weaponry and armor is used by the NiiVan.
Mercury weapons are actually made of a mercury-yttrium alloy, and the mercury in them is highly toxic so the weapons are quite effective and can incapacitate enemies without killing them. This is good for the NiiVan since they are generally pacifists and do not believe in murder.
Mercury arms are forged at temperatures around 90 degrees Farenheit because mercury does not freeze until 60 degrees after purification. This makes the process completely safe except for the toxic effects of the mercury, which are easily preventable.
Mercury War Axe
Mercury armor is much more widely used than the weapons are, as each individual is given a custom set upon graduation from First College (NiiVan have three levels of college.) The armor sets vary slightly in effectiveness and clever techniques are in use to boost their rating, such as Fel-Kor's use of special boron finish.
Mercury armor is forged at higher temperatures than the armor and bromine is a common catalyst to speed up the process. It is a light armor but is able to support the NiiVan greatly because it allows for flight that is relatively unburdened. Hylains would find the armor equally useful if a set were made for near-humans, but heavy warriors like Zake would dislike it. Shiek is a prime example of a fighter who would not benefit from the mercury armor.