Energizer (Kate "Katie" Power), is a fictional character in Marvel Comics' universe.
Katie began her superhero career as Energizer. She could disintegrate any kind of matter, including water and air molecules, store the energy and expel it in balls of explosive energy. Katie's Energizer power was highly destructive, potentially lethal, and in various issues, was able to destroy buildings and bring down supervillains such as Kurse. Katie initially had little control over her power, and tended to use it when she was frightened or angry, but as the series progressed, she gained control over her abilities. During the Snark Wars, Katie voluntarily relinquished her energy powers to the Snark prince Jakal. Her siblings had already had their abilities forcibly taken from them by Jakal. In the ensuing battle, the powers reverted back to the Power siblings one by one and Katie ended up with Julie's flight powers.
While she held Julie's flight powers, Katie was known as Starstreak. She was able to fly quickly, leaving a stream of rainbow light in her wake. While Katie as Starstreak was never able to break the sound barrier as her sister Julie supposedly did, she did refine the power by developing hovering abilities.
During Power Pack's mission in the Technocrat's space station, Katie regained her original energy powers. She continues to use these abilities under her original name of Energizer.
Katie also owned a gold Kymellian coin, which was a present from her "honorary godfather," Lord Byrel. Both the Pack's enemies and allies were able to use the coin as a tracking device to locate the team.