Jack Power

Jack Power
Mass Master, on the cover of the 2000 miniseries.
Publication information
Publisher	Marvel Comics
First appearance	Power Pack #1 (August 1984)
Created by	Louise Simonson (writer) June Brigman (artist)
In-story information
Alter ego	Jack Power
Team affiliations	Power Pack
Notable aliases	Mass Master, Counterweight, Destroyer
Abilities	Density and size manipulation Healing powers Formerly: Gravity manipulation Energy absorption, projection and disintegration

Jack Power, currently known as Mass Master, formerly Counterweight and Destroyer, is a fictional character in Marvel Comics' universe. He first appeared in Power Pack #1 and was created by Louise Simonson and June Brigman.

Jack was a founding member of the superhero team Power Pack. The second youngest of the four Power siblings, he was 8 1/2 years old when he was given his powers by Aelfyre Whitemane, a dying Kymellian noble. He continued to operate with Power Pack through their entire history.

Jack Power was born in Richmond, Virginia. Brash and ornery, Jack was the "wild child" of the Power siblings. He frequently insulted and argued with both his teammates and his adversaries. Queen Maraud, Power Pack's archenemy, feared him more than the other children because she thought he would be the most likely to take advantage of the lethal nature of his powers.

However, his bold nature also made him a key fighter for the team. He possessed a tremendous amount of loyalty and courage, and usually kept a cool head even during stressful situations. Jack jumped into the East River to help his sister Katie escape from an ocean liner. He even taunted the Snark Jakal who was about to kill him with "Can't even kill someone until Mommy tells you to?!".

Jack was perhaps the most innovative member of the Pack in terms of developing new power variations. When he received new powers, he was able to figure them out quickly and invent new uses for them. He was significantly better at controlling his gravity powers than Alex.

Recently, Jack retained his bold personality, but also showed a kinder, gentler side, opting to leave the team to care for his mother.

Jack was 8 in the original series; in the 2000 miniseries, he was 12, though this would suggest Jack had aged four years where his siblings had aged only three. Considering Julie Power, his older sister of two years, is now 17, Jack may now be 15 by proxy if his age in the 2000 miniseries factors canon to Marvel writers. In the All Ages 2005 miniseries comics (set in an alternate universe), Jack is 10.