(CNN) -- He's the strongman behind the strongman: Maher al-Assad.
The younger brother of Syrian President Bashar al-Assad, Maher al-Assad is described by analysts as someone even more ruthless than Bashar.
"Maher is the kneecapper. He is in charge of keeping the regime in power," said Joshua Landis of the University of Oklahoma.
It's a role he seemingly relishes. One analyst who has been in meetings with Maher described him as wearing a dark suit, sunglasses and slicked-back hair: a "Mafia wanna-be."
"This fellow thinks of himself as the family enforcer," said Ted Kattouf, a former U.S. ambassador to Syria.
Officially, Maher is in charge of two of Syria's most elite military units: The army's Fourth Armored Division and the Republican Guard. But he is also a leader of the Shabiha militia, a group of regime enforcers made up of mostly of minority Alawite Muslims, the same sect the Assads belong to.
The Shabiha, Syrian analysts say, has not only become a key part of the regime's fight against the uprising, but has also been responsible for massacres of Syrian civilians.
"Maher has been at the forefront of the most brutal fighting," Landis said.
Man of mystery
Maher is as shadowy as he is allegedly brutal. "We know precious little about him," said Landis.
He is rarely seen in public. He moves around regularly and avoids speaking on the phone. Very few photographs of him exist, and most of those were taken when he had to appear in 2000 at the funeral of his father, Hafez al-Assad.
Some of that mystery may be an effort to keep him alive, according to Landis. He is Bashar's last surviving brother.
Even his current physical condition is unclear. Many believe he was injured, maybe even losing a leg, during an attack on a Syrian national security meeting in 2012. Others believe the attack may have paralyzed his arm. He hasn't been seen publicly since.
With secrecy comes legend. One of the most widely circulated stories about Maher involves his sister, Bushra, who wanted to marry a man who had children from a previous marriage. While the entire family was scandalized by the marriage, it was Maher who reportedly shot his future brother-in-law in the stomach during an argument.
The story, widely reported but never confirmed, is indicative of his overall character, Kattouf said. "What the story does tell us is that he's impulsive, impetuous and brutal."
They are qualities that seem to have only improved his reputation.
While Bashar seeks to portray a positive image with the Syrian public, "everyone sees (Maher) as one of the major powers behind the throne who can do the dirty work," Landis said
'An "Entertainment Tonight" kind of guy'
But Maher also has more mundane interests beyond keeping his brother in power, according to Kattouf. In meetings with Arab officials, Maher has been described as quiet and uninterested in politics and current affairs.
"No matter what they brought up, he showed no interest, it was only when they started talking about gossip about Arab actresses and singers and who was sleeping with who, that's then he was into it. He's an 'Entertainment Tonight' kind of guy," Kattouf said.
That might be just fine with his brother Bashar, who seems to value family loyalty above an interest in world affairs. Bashar has intentionally installed relatives in key positions in an attempt to "coup-proof" his regime, according to Landis.
Bashar has apparently found the perfect family member to do just that.
"Maher sees himself as the protector of the regime," said Kattouf. "He's an ugly, ugly guy.