Z is a villain from Tenchi Muyo!.
Not much is known about him.
Just that his race tried to attack an anomalous part of the universe, and were slaughtered.
During this traumatic event, great power awoke inside him - Light Hawk Wings. He quickly used these to dispatch the enemy. Soon, he was beset by Tokimi, one of the Three Goddesses. After an undefined amount of time, Z became her emmesary, causing chaos throughout the multiverse.
Eventually, he grew jealous of Tenchi Masaki and sought him out. After a battle that he was dominating in, Z is stopped by the Three Goddesses. He then tried one last attack, cutting Tenchi into. Unfortunatly for him, this let Tenchi's omnipotence shine through, and he was vapourized. Tokimi apologetically recreated him and sent him back to his birthplace, albeit without the light hawk wings.