Though not all of Wikipedia's brutal warriors will exhibit these traits in equal proportions, they are very certain markers:
VICIOUSNESS Massive deletions, reverts, or tagging, across multiple articles, in a matter of minutes. As Machiavelli said in The Prince, when you're going to commit a bunch of evil deeds, do them as quickly as possible.
VINDICTIVENESS Point out the viciousness of a brutal warrior and you'll get retribution dressed up as your alleged failure to obey Wikipedia's policies. Criticizing a brutal warrior is "trolling," because brutal warriors see themselves as the personification of Wikipedia.
VARIETY Brutal warriors edit a wide variety of articles, because they have expertise in only one subject: wiki-war. Very few doctors, scientists, lawyers, artists, etc., edit Wikipedia, and they usually know well enough to limit themselves to topics they actually know something about.
VOTING Brutal warriors vote on everything there is to vote on in Wikipedia: articles for deletion, adminship nominations, block requests, etc. Often, those votes vastly outnumber article edits. To become an admin on Wikipedia, the support of brutal warriors is essential. That goes a hundredfold for ArbCom.
VENEER To cover up their viciousness and vindictiveness, brutal warriors maintain an appearance of civility. You will very rarely see a brutal warrior using profanity, and when they do use profanity, it is not directed at someone. For example, they might say, "that book is #@$&!" but they will never say "you're an ^@$#*!"
But of course this is a very shallow look at the psychopathology of Wikipedia's brutal warriors.