JLA #28: Grant Morrison and the Gang
JLA #28, the first part of "Crisis Times Five" was a Grant Morrison JLA/JSA story that also (briefly) featured a few foes of the Pre-Crisis Supergirl.
First, a Who's Who entry for Matrix Prime:
The Gang and the robot Matrix Prime were villains in the SUPERGIRL series of the early 1980s. The DCU Guide for this issue speculates that Kong, Bulldozer and Matrix Prime (with Brains' mind) are now Power Girl villains.