|Weapon: Large broadsword|
|Blood Type: Unknown|
Zero (μηδέν) made first and only appearance in Battle Arena Toshinden 4, as one of the unlockable sub-bosses.
Zero is an artificial being, created by the Gerard Foundation, who revels in destruction. One day, he obtained a wound during an accident in an experiment that seemed to create an opening to some form of power. He killed the scientist who created his current state and soon after, discovered that a special suit existed that when worn, released even more of the mysterious power he possessed into him.
However, the amount of power that he was amassing frightened the Shitennou and Master to the point that they sealed Zero away, so he was no threat to them. After a long time, thanks to the new Master Eiji Shinjo's influence, Zero managed to break the seal and free himself. Joining Eiji's team as an executive of the Foundation along with Eos, he went out to find the Four Sacred Arms, although his reasons for doing so is rumored to be for his own ambitions.