Jose Roberto Carrasco Pizarro's nom de guerre is Santiago.
The Chilean with the stubble, black shirt and black cap first came to the public's attention in August 2015 when Colombian media reported that the security forces had found two passports and an ID belonging to a Chilean citizen in a Farc camp they had attacked in central Colombia.
In an exclusive interview with the BBC in the jungle of western Colombia, Santiago remembers how when he first joined the Farc, he went by a different alias.
"They first called me Agustin, but it reminded me of Augusto Pinochet [the right-wing general who ruled Chile between 1974 and 1990] so I changed it to Santiago, like the Chilean capital."
'On the side of the poor'
Santiago is 33 and from the Chilean port town of Valparaiso.
He studied to become a publicist in Vina del Mar and continued his training in the Spanish city of Barcelona.
It is a career choice he now regrets: "The publicist is a sort of Devil's advocate, because he sells products that are not needed."
His rhetoric is anti-capitalist through and through, but what made this young Chilean from a middle-class family join a rural guerrilla group thousands of miles from his home country?
"I like the Farc because they have always been on the side of the poor," he says.
"Big business doesn't respect borders, why shouldn't we revolutionaries join forces to defend ourselves?"
"Borders only belong on maps," he explains.
Most Colombians do not share his view of the Farc as a force for good.
They point to the massacres and bomb attacks carried out by the guerrilla which have landed the Farc on the list of terrorist organisations of both the European Union and the United States.
Seeking out the rebels
Santiago joined the Farc a couple of months before the start of formal peace talks between the government and the guerrilla group in November 2012.
He recalls that it was not easy to track his future comrades down, even though he would head to areas where guerrilla action had been reported.
It was only after eight months spent in rural areas of central Tolima province that Santiago was finally able to make contact with the Farc.
After some initial mistrust, with the Farc suspecting him of being a spy, Santiago was finally allowed to join their ranks.
He was trained to be a nurse and was deployed in two combat situations.
Among his worst memories are the time when a guerrilla camp he was in was bombed by the security forces.
Three rebels died in the attack, two of them when the bombs fell straight on them.
Santiago says there was nothing left of them.
The third died in his arms.
Santiago says he survived the bombing because he had a habit of sleeping next to a big tree. The trunk protected him from the blast.
Fear and alertness have now become part of his life.
"When I hear a dog barking, I wake up even from the deepest sleep and reach out for my rifle," he says.
Longing for Chile
While Santiago is in a relationship with a 30-year-old fellow Farc rebel, he has no relatives in Colombia.
Being close to his family is something he misses, even though he professes himself to be happy with his life in the guerrilla.
"I miss everything about Chile: my family, the places. I grew up in a very close family."
Santiago says his family does not share his views.
While his sister is involved in politics - she is the mayor of the town of El Quisco, 40km south of Valparaiso - she belongs to the centrist Democracia Cristiana party.
Santiago is not the only foreigner to have joined the ranks of the Farc.
Dutchwoman Tanja Nijmeijer is probably the most famous foreign recruit. She is part of the Farc delegation negotiating a peace deal in the Cuban capital, Havana.
But there are others, including a French woman and, according to Santiago, a Venezuelan and an Argentine.
Santiago says the prospect of a peace deal between the government and the Farc does not inspire him with much confidence.
In June, the two sides agreed on a bilateral ceasefire after more than five decades of conflict.
But Santiago says government forces are not the only enemy of the Farc he worries about.
"The government is holding out its hand to us there [in Havana], but here we have the paramilitaries," he says referring to the right-wing groups created to fight the Farc.
The government argues that the paramilitary groups demobilised a decade ago and no longer pose a threat, even if some individual members may have joined armed criminal gangs.
But Santiago says they are still a danger to the Farc, especially once the guerrillas lay down their arms.
"I think they will kill many comrades," he says. "I will not sleep peacefully."