Born Dr. Demetrios Vasilikos, he worked with his father as one of the best father-son medical teams in Paragon City.
That partnership ended, though, when his father contracted an alien virus after treating a superhero. Although he tried everything in his power and within the scope of medical science, his father still died.
That one moment defined and changed Vaskilios. His obsession on saving lives transitioned from saving his father's life to bringing his father back to life, to bringing everyone back to life, and to eliminate his own fear of death.
To that end, he delved into using experimental drugs to re-animate dead tissue. His first subjects were patchwork creations from various fresh corpses. He had some success with those, but the beings that were brought back to "life" were semi-mindless. They became his minions, gathering more bodies for his experiments.
Unfortunately this attracted the wrong kind of attention. Various hero groups began looking into the grave-robbing, which forced the doctor to get more help. Medical schools provided some help, along with a list of disgraced medical professionals deemed too "dangerous" to work for The Family or Arachnos.
Then he began to experiment on himself, trying to find ways to work harder and longer without needing rest or sleep. This was the end of everything that was Vaskilios. He ceased to be the human doctor in both body and soul and he became that which his own minions first called him: Doctor Vahzilok.
At one point, he began to get help from other sources in exchange for fresh (living) bodies as part of the Omega-Genesis Program. He agreed to help as long as he was promised a new body for himself. Sadly, the Freedom Corps raided the facility and (reportedly) killed Dr. Len Zarus, depriving him of his much-needed new body.
Eventually he was stopped by Paragon City's newest hero, Galatea Powers. He was convicted for his crimes and sent to prison to serve multiple life sentences.
At one point, Dr. Vahzilok was approached by Malcolm Rochspare, a corrupt attorney who offered the doctor a way out of his multiple convictions.
Unfortunately his motion for a retrial was put on hold when it was revealed that Rochspare's clerk was too careless and was on the verge of being discovered. Vahzilok's minions moved to eliminate the clerk, but in the process set off alarms in the Judicial Center. This brought Galatea Powers back for a rematch, which was decidedly in her favor. His motion for retrial was denied and he was sent back to prison, this time with new convictions added to his already extensive multiple life-terms.
Powers and Abilities
Doctor Vahzilok's true power rests with his ability to create undead minions and bend them to his will. But if he doesn't have time to literally build an army of patchwork soldiers or re-animated lackeys, he's far from helpless.
Thanks to his self-experimentation, he gave himself a massively-bulked body, capable of withstanding a lot of physical abuse. Plus, because he is his own creation, he cannot feel any pain. He can lose whole parts of his body and never feel it.
In addition, he has a large assault weapon grafted to his right arm, which is the real reason for his massive bulk. This gun can fire 50 rounds of ammo-piercing ammunition per second, or one grenade projectile every sixty seconds.
Plus, he is a doctor, so he has a few scalpels hanging around. Just don't ask where he hides them. It's just not sanitary.
Another very dangerous weapon at his disposal is his knowledge of the human body and how to destroy it through biological and chemical means.
Doctor Vahzilok sees himself as a man on a mission to literally end death. Although not perfect, he sees his creations as ongoing attempts at fulfilling his quest. He is amoral and sociopathic and certainly homicidal.
(See his Paragon Wiki entry for more information.)
Although referred to several times in "Guardians of the Dawn Spotlight", Dr. Vahzilok himself was not seen until Issue #16 when he appeared in flashback, and in "The Guardian Powers" #10 when he was defeated for a second time by Galatea Powers.