Jack Power was the third oldest of four children of both Doctors James Power and Margaret Power who were killed by the Snarks-Gnucci Crime Syndicate due to their breakthrough in quantum physics. Jack along with his other siblings met an alien Kymellian named Linus Whitemane whose son was also murdered. Angered by this, Linus empowered the kids with the abilities of his people and taught them to wage war against criminals as the vigilante group Punisher Pack.
Jack took on the codename Mass Master and followed his siblings on a murderous rampage against the syndicate for a long time. The leader, Ma Snarks-Gnucci created Snark-Human Hybrids to reinforce her empire, but Katie and the others stopped her every time. The Punisher Pack finally came to the end of the road as Ma Snarks-Gnucci was their last target. Jack and the group decimated their opponents killing all of them.
They made it back to their base where they were greeted by Linus as Jack's brother Alex reported to him that their mission was completed. Linus was so glad to hear that and told Jack that they can all return to a normal life. Not happy with his sudden words, the Power children said that their lives were over the day their parents were killed. As the group stood there, Jack said that there were others criminals out their who needed to be punished, but Linus said that wasn't their responsibility anymore.
Jack and his siblings asked if Linus was going to stop them but they all decided to leave Linus in order to continue on their path of vengeance. Linus started to blame himself for the children's behavior and took it upon himself to now put a stop to them.
- 1 appearance(s) of Jack Power (Warp World) (Earth-616)
- 1 image(s) of Jack Power (Warp World) (Earth-616)