The North Korean lauded by Donald Trump in a State of the Union address is seeking a seat of his own in the South's parliament to defend other defectors who have fled their reclusive homeland but often find themselves marginalised.
Ji Seong-ho was stealing coal to feed his starving family during a devastating 1990s famine when he fell from a train wagon.
The drop knocked out the then 13-year-old and a train ran him over, severing his left leg and hand. He was rushed to hospital and operated on without anaesthetic.
"My father was given a bag with his son's hand and leg" to bury, Mr Ji recalled in an interview with AFP.
"This was what he got for being loyal to the Party."
A quarter of a century later and on the other side of the Demilitarised Zone that divides the Korean peninsula, Mr Ji is running for South Korea's main opposition, the conservative United Future Party, in legislative elections.
The vote takes place on 15 April, the same day the nuclear-armed North will celebrate the 108th birthday of its late founder Kim Il-sung.
Mr Ji's father was a loyal rank-and-file member of North Korea's ruling Workers' Party.
But that did nothing to protect his son from frequent beatings by guards who said his disabled body was "a disgrace to the Dear Leader" Kim Jong-Il - Kim Il-sung's son, and father to current ruler Kim Jong-un.
"I was crippled... because of a problem in the government, but they blamed us and tortured us," said Mr Ji, who fled the North in 2006.
Swimming across the Tumen river to China with his brother's help, he went on a 10,000km, six-month odyssey through Laos, Myanmar and Thailand to reach South Korea, where he was given a prosthetic leg and hand.
"I was able to walk again," said Mr Ji, who went on to study English, typing with one hand as he eventually obtained a master's degree in law.
Mr Ji, now 38, works as a rights activist running an organisation that has helped around 500 North Koreans make their way clandestinely through China and into third countries from where they can travel to the South.
His office is lined with photos with top officials including President Trump, who in his 2018 speech to Congress called the defector's story "a testament to the yearning of every human soul to live in freedom".
Next to Mr Ji's desk stand the wooden crutches made for him by his father that he waved in the air in front of the world's cameras.
His father also tried to flee shortly after Mr Ji's departure but was caught and tortured to death, he said.
Mr Ji, who is standing for a proportional representation seat, feels the 33,000-odd defectors in the South have been neglected by the current government in Seoul.
President Moon Jae-in held three summits with North Korea's leader in 2018, including a meeting in Pyongyang, but human rights issues have largely been off the table.
"The entire society of North Korea is a prison," Mr Ji said.
"When the peninsula is reunified, are we going to shake hands with the North Korean regime? How are we going to look the North Korean people in the face?"
Last year, the South's government forcibly repatriated two North Korean sailors suspected of killing 16 fishermen - a move that defectors and activists say amounted to a death sentence.
Next week's vote does not affect Mr Moon's position as he is directly elected, but it is largely a referendum on his performance after nearly three years in power.
And with negotiations at a standstill, North Korea has barely figured as an issue.
Meanwhile Pyongyang's propaganda outlet Uriminzokkiri has called Mr Ji "cruel and brutal human scum" who fled after committing numerous crimes.
He was plotting against Pyongyang and "cheating his dirty deeds in order to get a little more money from the hostile forces", it said.
Defectors who do reach the South sometimes struggle to adjust to their new life in a democratic, capitalist society.
Last year, a 42-year-old woman and her six-year-old son were found dead in their home - along with an empty fridge and unpaid bills - two months after their deaths.
The incident sparked outrage among the defector community, who called on the South's government to improve support programmes for new Northern arrivals.
"Successful resettlement would show the North Korean people that free democracy is good," Mr Ji said, adding: "If we can't settle, Kim Jong-un will be laughing at us."