“The Grim Reaper”: Closer Rafael Soriano has also been compared to a mafia hit man by fellow reliever Drew Storen. (Toni L. Sandys/The Washington Post)

Out in the Washington Nationals’ bullpen, Rafael Soriano throws his warmup pitches softly, except the last one, which he fires as hard as he can. He spins on one foot, walks to the gate and jogs from the outfield to the middle of the diamond. He speaks into his hat and writes in the dirt with his finger. He does not share those words; not even his mother knows, he said. Soriano, finally, climbs to the rubber and faces the hitter, his face placid, his temperament ice cold.

“The Grim Reaper,” outfielder Jayson Werth said. “He doesn’t come in to get you out. He comes in to steal your soul.”

A month into his tenure in Washington, Soriano has given the Nationals what they expected — experience and inevitability in the ninth inning. At two years and $28 million, he didn’t come cheap. But after a choppy start, Soriano has pitched 10 straight scoreless innings and converted eight save chances in a row. He has closed 13 of the Nationals’ 17 victories and blown only one lead. His countenance has remained the same, betraying nothing.

“I’ve been doing a lot of years,” Soriano said. “I don’t try to change nothing. I do it good so far. There’s no reason to change. That’s how I do it.”

All four wins of the Nationals’ recent road trip concluded the same way. Soriano jogged from the bullpen. He fired cutters and sinkers until his work was done. After the three saves, he untucked his shirt, his ritual representation of a job well done.

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“He’s Léon: The Professional,” said Nationals reliever Drew Storen, referring to the 1994 film of the same name about a mafia hitman. “Have you ever seen that movie? That’s what he is. That’s the beauty of the bullpen. We have guys that are wired differently.”

After his save Saturday, shortstop Ian Desmond and Werth joined Soriano in ripping their jerseys out of their pants. He had implored Desmond to join him from the start of the season.

“I’d been telling him, ‘You got to do it,’ ” Soriano said. “The first two or three games, he didn’t do it. I say, ‘Bro, why?’ ”

“At first, he got mad I wasn’t doing it,” Desmond said. “I said, ‘Hey, I got to think about it. You’re throwing a couple too many balls. Let me make sure that you’re the real thing.’ I wanted to do it. I’m not going to leave him on the island out there by himself.”

Soriano, 33, hopes other teammates join him in his small celebration. When he pitched for the Tampa Bay Rays in 2010 and saved 45 games for a playoff team, Soriano enjoyed how so many Rays — Evan Longoria, Carlos Pena, B.J. Upton — untucked with him.

“With the Yankees, nobody do it,” Soriano said. “With the Yankees” — he rolled his eyes — “people get mad.”

Soriano rarely felt at home in New York the past two seasons. At his introductory news conference, General Manager Brian Cashman announced he opposed signing him. Fans punished Soriano for an injury-truncated, 4.12 ERA season in 2011. Even last year, as he saved 42 games, he received criticism for, of all things, untucking his shirt after saves.

“They tried to make it a big deal, for why I do it,” Soriano said. “I’m not making the hitter mad. It could be a groundball, strike him out. I’m not trying to pimp it, like [Jose] Valverde. I don’t think the hitter feels mad at me. I do it because I feel it in the moment. I do what I think I can do to make me feel good. I like to feel good about myself.”

Washington, quickly, has grown on him. He enjoys the city and his teammates. It took saving 42 games after replacing Mariano Rivera for New York to accept him. After allowing runs in two of his first four games, he has already settled in.

“Right now, I feel the same way after I’ve been two years with the Yankees,” Soriano said. “Tampa was the same. The first couple games, I don’t feel well. But now, I feel comfortable.”

Teammates, too, have grown comfortable with him. In spring training, he often walked into the clubhouse after everyone else had arrived. He blared bachata music and received glances with eyebrows askew. But when the Nationals played in Atlanta last week, he invited the entire team to his home for dinner and drinks following their game Monday night.

“It’s funny, because you look at him, and he’s scary,” Storen said. “But then you start talking to him, and he’s smiling, laughing. You’re like, ‘Oh, okay.’ He switches gears pretty quick.”

Saturday afternoon, Storen warmed up next to Soriano and laughed at the disparity. Like most relievers, Storen grunted and threw gas, all hissing air and snapping leather. Soriano lazily kicked his leg and tossed pitches as if playing catch the backyard, his face blank. Other closers jump in the mosh pit; Soriano sits in the balcony.

“It never gets out of control for him,” Desmond said. “That’s probably the coolest thing to see. . . . He never shows any emotion until he untucks his shirt. There’s a reason why he’s got all the money and the saves. Because he’s composed.”

Soriano’s ability to read swings and adjust his approach reminded Desmond of Livan Hernandez. He can manipulate his fastball and cutter, forming different variations and throwing it to different locations based on the hitter.

“It’s a little bit of everything,” Chicago White Sox first baseman Paul Konerko said. “He does have some velocity. He does have stuff — it’s not like he doesn’t have anything. He’s got some command and he can throw in and out with that cutter, so the plate can get kinda big. The plate seems bigger because he can throw it in and throw it out. And he throws strikes. He doesn’t shy away from contact.”

Soriano described his aggression as purposeful, but his deceptive style as part-accident. He pitches as though he makes subtle manipulations of the ball, throwing two pitches that look identical until they break differently at the end. This, he says, is beyond his control.

“Sometimes, the ball just moves,” Soriano said. “I don’t try to do it. Sometimes it moves, like 90 percent of the time. I feel comfortable with that. There’s no reason to change now.”

Twelve years and five teams into his career, Soriano does most things in his own way. As the Nationals are finding out, his way works just fine.

James Wagner contributed to this report.