Hyss is Cäer's longdagger.

It is a unique weapon crafted by his father for a renowned assassin, who one day passed it on to Cäer as a token of the fine craftsmanship, to honor his father and to thank him for the many times the weapon saved his life.

Hyss is most lethal not for the razor sharpness of the blade, but because the snake’s head and body on the longdagger holds a lethal poison that can be release throughout the weapons tiny pores that were forged into the steel when the blade was made. With the press of a hidden button in the correct manner, the poison is released into the victim.

The name comes from the hissing sound created as the poison is release.