When you're talking about mixed martial arts and the name "Cyborg" comes up, the words that spring to mind are strength, toughness, relentlessness and, more than anything else, dominance. Strikeforce women's middleweight champion Cristiane "Cyborg" Santos has displayed all of those qualities in abundance.

Now her husband has a chance to add to the luster of the nickname the couple share. If Evangelista "Cyborg" Santos can beat welterweight champion Nick Diaz in the main event of Strikeforce: Diaz vs. Cyborg on Saturday night in San Jose, Calif., the Brazilian husband and wife will have matching title belts for the family trophy case.

"After 15 years of training and sacrificing, my dream is finally almost here," Evangelista Santos said at a Strikeforce news conference on Thursday. "I am very excited at the chance to make my mark."

Make his mark, indeed. The Cyborgs -- they've adopted the name as a last name more than a nickname -- are not the most famous or accomplished sports couple. That distinction would probably go to Steffi Graf and Andre Agassi. Or Mia Hamm and Nomar Garciaparra. Or Florence Griffith-Joyner and Al Joyner. But more than any of those others, the Cyborgs are the couple you'd least want to mess with if you saw them strolling arm-in-arm on a moonlit night.

Cristiane's brawniness speaks for itself. If you need a translation, ask Gina Carano, whom she pummeled in 2009 to win the Strikeforce title, or Jan Finney or Marloes Coenen, both of whom she KO'd last year to remain champ. As for Evangelista, the Muay Thai kickboxer who trained for years at Brazil's renowned Chute Boxe Academy, is a ruthless and powerful brawler who doesn't have a reverse gear.

In terms of career success, however, it's been a roller-coaster ride for Evangelista Santos (18-13). He's won his last two fights, but lost the two before that. Prior to that came a win preceded by two more losses. That's the way it's gone, pretty much from the time he made his debut in Brazil back in 1997, lots of ups and downs.

So how has Santos ended up in a title bout? Part of the reason is that the timing didn't mesh for Strikeforce to match Diaz against his most logical challenger, Paul Daley. So Scott Coker and Co. apparently decided that the next-best thing would be to put slick-striking Nick in with someone whose forward-moving style should make for an entertaining fight.

It actually could be an entire evening of entertaining fighting Saturday on Showtime (10 p.m. ET). In addition to the main event, there's also another title bout, in which middleweight champ Ronaldo "Jacare" Souza defends against Robbie Lawler in one of those classic striker-vs.-grappler chess matches that'll be decided by whether the fighting takes place while standing or on the mat. That also will be the storyline when 3-0 light heavyweight Roger Gracie, of the first family of Brazilian jiu-jitsu, faces his biggest test yet: the well-rounded Trevor Prangley, who is coming off a win over Keith Jardine. And, of course, there's 48-year-old Herschel Walker vs. Scott Carson, a fight that'll attract a lot of curious non-MMA sports fans to the telecast.

But Diaz insists that the main event is going to be the evening's big attraction. "I feel good and I'm ready to fight," he said at the news conference. "Cyborg has a unique style, and I know that he will give it his all and be as crazy as ever. But that's good, because I'm crazy, too."

And in case anyone was wondering whether he'll be crazy enough to look past Saturday's fight to a possible matchup with Daley or even a dream fight with Georges St-Pierre, Diaz made a point of talking up Santos as a title contender. "I have great respect for Cyborg," he said. "He is strong and has skills and comes real hard. I feel he deserves a shot."

One factor in Santos' favor is that when the longtime middleweight dropped down a weight class for his last fight, in June, he showed added speed without a loss of power in knocking out Marius Zaromskis midway through the first round. It was a more lopsided beating than Zaromskis had taken in his previous fight, six months earlier, when he rocked Diaz before succumbing to the champ late in the first.

Diaz noticed. Perhaps he's just building up his opponent before knocking him down, but he speaks of Santos as a sizable obstacle to overcome. "I always tell people if they are too small for 185 pounds, they should come down to 170. I usually call people out for being too small at that weight," he said in a media conference call last week. "But I wouldn't point the finger at him for that one. I think 185 is probably a better weight for him."

However, the man who was nicknamed "Cyborg" long before he met the former Cristiane Venancio is not putting much thought into what Nick Diaz or anyone else thinks of him. "I am not worried about those who underestimate me in this fight," he said. "I am preoccupied with winning. "

Gotta keep up the family nickname.

Questions? Comments? To reach Jeff Wagenheim or contribute to SI.com's MMA mailbag, click on the e-mail tab above.

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