OAKLAND — The Warriors’ Stephen Curry is as kind as any young man you will meet, more down to earth than any global celebrity you could come across.

Curry, the NBA’s Most Valuable Player, chats with strangers as if he is an average Joe. He signs countless autographs and regularly takes pictures with fans.

That is Curry off the court. But when he puts on that No. 30, he becomes another person. His alter ego takes over. And that guy is merciless. He takes pleasure in preying on defenders, in piling up victims in his quest for the spectacular.

A decade of being doubted has created a monster inside of Curry.

Kids on Charlotte playgrounds overlooking the short, skinny kid lit a fire in him. Big-time colleges bypassing him — including Virginia Tech, where his parents were star athletes — stoked the flames. Being written off after a rash of ankle injuries prompted him to set the league ablaze.

Curry has made it to the big stage of the NBA Finals, has become a marquee player in this league, because of that other guy. The alter ego completes the total package that vaulted him to MVP status, maybe to champion, maybe to the Hall of Fame. He has Steve Nash’s skills, Magic Johnson’s flair and Isiah Thomas’ killer instinct.

“He’s a humble human being who has an arrogance about his game,” Warriors coach Steve Kerr said. “When you have that type of confidence and fearlessness to take the shots that he does, and make them … it’s a good arrogance. It has to do with his confidence in his skill set. It’s what makes him who he is on the court just like his humility is what makes him who he is off the floor.”

Curry doesn’t just want to succeed, he wants to amaze. He doesn’t just want to win, he wants to dominate. Teammate Shaun Livingston loves that about Curry.

In his 10th season, and on his ninth team, Livingston said Curry has a reputation around the NBA for being lethal. Not just because of his deft shooting or the multiple ways he can attack a defense. But he has a mindset that leaves opposing coaches on edge.

Livingston describes Curry as “a killer” who is just as willing to light up the worst teams as he is the best. Most don’t know how competitive Curry is because he’s such a warming figure off the court.

But NBA players know. And opposing fans have learned.

Houston fans know after he drilled a corner 3-pointer in Game 3, took out his mouthpiece and stared at the crowd. Dallas fans know after he screamed “We Out! We Out!” after he broke the Mavericks’ heart with a game-winning buzzer beater. New York fans know after he put up 54 points in Madison Square Garden, including a zombie gallop after one of his 11 3-pointers.

Curry’s teammates love that he goes for the jugular.

“When we’re going on runs and he is just hitting daggers, I love that,” Livingston said. “We’re already going up, but he ain’t looking for anybody else. He’s looking for 3s. And they’re just back-breakers. The ones you’ve got to just call a timeout. Against Memphis, when he was going in that series. In Houston for Game 3. Man … just break their neck. Don’t even give them hope.”

Nobody knows that better than Curry’s younger brother, Seth.

When they played pick-up ball in Charlotte, Seth watched his brother respond to slights by giving bigger players the business. He also received the business from Stephen.

“He would never let me win,” Seth said.

The two would argue a lot, and occasionally it would escalate into some brotherly scuffling. When they played together at Charlotte Christian Academy, Seth a sophomore and Steph a senior, they once had it out in practice.

They would be on opposite sides going at each other. Seth said their father, Dell, who played 16 seasons in the NBA, was an assistant coach and would prod his boys, turning up the intensity. Steph delighted in frustrating his competitive little brother.

He carries that same delight in the NBA.

That was never more evident than in a March game in Los Angeles when his double behind-the-back dribble left Clippers star Chris Paul splayed on the floor. Curry said when he saw Paul go down, he immediately pulled up for the shot to finish the play. It was crucial that he made the shot to complete the embarrassment of Paul. Because that’s how the other Curry rolls.

It is no wonder his favorite nickname is the Baby-Faced Assassin. He said it has sentimental value. It first cropped up when he was in college, and it really embodied the alter ego he was developing.

Back then, before the muscles and the goatee, he looked impossibly young — like an adolescent not to be taken seriously. His youthful appearance made him ripe for teams to pick on, for players to bully.

The nice guy who brings his 2-year-old daughter to the postgame news conferences … who sits in the crowd with Giants fans rather than in a private suite … who still drops in on a group of New Jersey high schoolers that reached out to him on social media four years ago … who publicly thanked little-known team employees in his MVP acceptance speech — that guy couldn’t settle for just being a good player.

He had to make examples out of defenders. He had to excel emphatically to help detractors get over his appearance of inferiority. And his alter ego is how he pulls it off.

It was that other side of Curry that captivated the country when he led Davidson College on an NCAA Tournament run during his sophomore year — when he dropped 40 points on Gonzaga, 30 on Georgetown and 33 on Wisconsin en route to the Elite Eight.

It was the other side of Curry who scored 22 points in a quarter twice in the 2013 NBA playoffs, his first postseason appearance.

It was the other side of Curry that has him alongside LeBron James atop the NBA mountain — and the Warriors on the cusp of a title.

Read Marcus Thompson II’s blog at blogs.mercurynews.com/thompson. Contact him at mthomps2@bayareanewsgroup.com. Follow him at Twitter.com/ThompsonScribe.