The hawkish North Korean general on his way to New York for pre-summit talks is a skillful politician who has thrived through three generations of the ruling Kim family.
Kim Yong Chol, described as Kim Jong Un's right-hand man, left Beijing on Wednesday bound for the North's "imperialist enemy" where he will meet US Secretary of State Mike Pompeo, and possibly Donald Trump.
The man blamed by South Korea for the 2010 sinking of a warship that killed 46 sailors will become the most senior North Korean to step on US soil in nearly two decades.
The meeting is the latest in a flurry of diplomacy as the two sides lay the groundwork for a historic first summit, planned for June 12.
The four-star general, who is believed to be in his 70s, has been at the forefront of Pyongyang's emergence from global isolation this year.
He attended the closing ceremony of the South's Winter Olympics in February, sitting just feet (centimetres) from Ivanka Trump.
He was by Kim's side when the young North Korean leader met South Korean President Moon Jae-in in April, and again for the leaders' surprise second summit on May 26.
But the march to become Kim Jong Un's most trusted general has been a long one requiring intellectual heft, nimble footwork and a willingness to take extreme measures.
Kim Yong Chol first donned the uniform of the Korean People's Army in the 1960s, when he was assigned to guard the heavily-fortified border that bisects the peninsula.
A graduate of Pyongyang's elite Kim Il Sung Military University, he went on to make a name for himself as an expert on the hated South Korean regime.
Kim often "explained everything about the South's political and military situation for more than an hour without looking at a script", defector and former army colonel Choi Joo Hwal told the Seoul-based Daily NK news website in 2016.
He won a series of promotions under the country's founding leader Kim Il Sung and even led the North's military delegation for talks with the South in 1989.
Kim "came to the attention of top leadership figures by hard work and accomplishment and not through patronage connections", the respected 38 North website reported.
Kim's role as a military interlocutor in dealings with the South continued under Kim Jong Il, but it was his rise to the top job at the Reconnaissance General Bureau, overseeing foreign spying operations in 2009, that made him notorious.
It was at Kim that South Korean intelligence pointed the finger of blame when the Cheonan corvette was torpedoed in 2010, and when artillery units shelled a border island, killing four people.
Seoul said the military man was manoeuvring to show loyalty to the regime as the power transfer from Kim Jong Il to his son was getting under way.
That shift was completed in 2011, when the untested Kim Jong Un ascended, carrying out a purge that saw many senior figures removed or even executed.
It was a purge Kim Yong Chol would survive, cementing his reputation as a hawk in 2013 when he threatened to break the ceasefire that ended the Korean War and to turn the US into a "sea of fire" with a nuclear strike.
But in the recent reconciliatory push he has also made efforts to paint himself as a more approachable figure.
Reportedly a gifted linguist, Kim has appeared at ease in international settings, and even attempted a joke with Seoul reporters who visited Pyongyang in April for a pop concert.
But it was a joke with a edge of steel, and a reminder of where his loyalties lie.
"I am Kim Yong Chol, the guy blamed by the South for the Cheonan ship sinking".