Captain Arsala of the Washington, DC Special Crimes Unit. Went after Dove, Dawn was trying to work out the whole secret identity thing and get him to date her as Dawn instead, eventually he figured out they were the same person. He and Dawn were camping when Monarch found them, blasted Sal into oblivion, and grabbed Dove.
Funny thing about Armageddon 2001 #2 is that you can see that they got halfway through the story before they decided to change Monarch’s identity. It’s supposed to look like a major red herring, but it’s way too choppy, plus if you take into account things like the following Justice League Europe issue in which Catherine Cobert has a nightmare about an evil Captain Atom, it strongly implies that CA was originally supposed to be Monarch.