The Birth: Massacre's appearance was highlighted in The Adventures Of Superman #509. An alien, violent; and I mean real violent by nature, one still remembers his introduction on the second page of the book : Thrashing around with Auron amongst the dead he himself had slain, with the giant title proclaiming Massacre in caps.
With Superman returning from the dead stronger than ever, a whole new horde of villains were created rather than the usual boring ones and this Massacre was amongst the few who stood out well. Till today, everyone is still clueless as to where this guy is from.

The Legend: Massacre's main mission in life seems to fit that of the warrior who has no goal except to destroy anything in sight. Maybe that's a sport for him. Wherever he's been shown, he's always been kicking ass and enjoying it. Probably the same satisfaction that a hunter enjoys after the kill.
Massacre had broken into a Virago cruiser and massacred everyone in sight. One of the opponents he fought was Auron, the clone of Jim Harper a.k.a Guardian created by Cadmus who held Superman's D.N.A code in his computer. Massacre thought he had finished Auron and so the guy took of into space leaving his skimmer to salvage anything valuable that he could. But the skimmer hid when he saw Superman flying in. Supes helped out Auron and the two tracked down Massacre where he was busy enjoying another battle. Massacre and Supes duked it out hard, Supes was quoted saying that he hadn't been hit that hard since Doomsday (seems that whenever someone new and strong came along, Supes seemed to compare him with the Armaggeddon creature) But the match was a draw as Massacre dealt a fatal blow to Auron and then just upped and went.
The second battle was fought on Earth, Superman's home ground. Massacre seemed to relish the thought of killing his prey on it's own turf. That match also ended in a draw after his skimmer was seriously hurt when the flyover he was standing on gave way. Massacre tols Superman that he could instantly get the bug admitted into a Xeno-Med but instead he took him and watched him die in space. Said this little twist made his battle with Superman a bit more personal.
Massacre has no need to lug heavy weaponery around. He enjoys using his fists - adds that personal touch. He is also capable of transforming into energy to traverse vast distances in space and to escape Superman. Looks like the guys at DC don't want to kill him off too soon, nor do they want to see him humiliated by defeat.

Adventures of Superman #509