Dark Oak

ダーク・オーク

The powerful leader of the Metarex, a large army of bio-robots that scours the galaxy for Planet Eggs, the main antagonist of the Metarex Saga and the final villain of Sonic X.

Spoiler

He was once Luchs (Lucas in the English dub), a male member of a plant-like species from planet Green Gate, Earthia's husband, and the biological father of Cosmo and Galaxina. Many years ago, his race was at war with an unknown army of animals. Earthia wanted to leave their planet behind and start a new life, retreating from their enemies. Being a warrior and the combat faction leader, Luchs would rather stay and fight to stop the enemyfrom causing further destruction in the universe, which incited friction between the couple. Eventually, Earthia told him if he did not like it, he could stay and fight the enemy himself. In a desperate attempt to defeat the enemy, Luchs extracted his home world's Planet Egg and tried to harness its energy to sustain his and his followers' monster forms without dying. Horrified that her husband has sacrificed so much to fight, Earthia called out for this betrayal, with the latter hypocritically doing the same to her for wanting to abandon their planet entirely. Earthia and all the female memebrs of the race left while Luchs and his fellow soldiers remained behind to fight for their lost cause.
Fearing the lengths her husband would go to end the war, Earthia ordered the remaining males to be killed and unleashed a nuclear strike that devestated their world. Luchs and the few that survived (four males who would become his most trusted subordinates as commanders of the Metarex) swore revenge against this betrayal. Perfecting their science, they used the Planet Egg to create powerful cybernetic bodies for themselves and vowed to end all conflict in the universe by eliminating all life except plants and plant-based creatures. Now referring to themselves as Metarex, they took new names for themselves and raised an army. From this point onwards, they crusaded across the universe, harvesting the Planet Eggs they required to achieve their final goal. At some point afterwards, they tracked down Earthia's space cruiser and on Dark Oak's orders, slaughtered everyone onboard, sparing only his and Earthia's last child, Cosmo.