User blog comment:LLight/WonderCon: Young Justice Season 2's Alien Invasion/@comment-209.221.49.37-20120318221902/@comment-1038387-20120319162324

Invading aliens. There's a lot of those.
 * 1990ish, there was an entire arc called Invasion!. An Alien Alliance invaded: Dominators, Khunds, Thanagarians, Gil'Dishpan, Durlans, Psions, Citadel, Daxamites, Warlords of Okaara and Spider Guild (and no, I didn't know these out of my head).
 * Older and other evil alien invaders/potentially invading empires include Starro (duh), Apellaxians (also JLA villains), Despero, the entire Fourth World (I don't think Darkseid's going to let someone else take over Earth), the Reach, Zamarons, Daemonites (some Wildstorm characters showing up would be nice), the Faceless Hunter, Controllers, the Branx, Tamaraneans, Hyathis/Kanjar Ro/that robot guy and lizard guy, Gordanians, and a truckload of L.E.G.I.O.N./Omega Men villains.