After leaving his upscale Cairo neighbourhood to fight with the Islamic State militant group in Syria and Iraq, Younes says he learned how to work as a sniper, fire heavy weaponry and behead prisoners using the proper technique.
One year later he harbours the kind of ambition that could create a security nightmare for Egyptian authorities: to return home and hoist the Islamic State's black flag in Egypt as his comrades have over large swathes of Iraq and Syria.
Eventually, says Younes, he and other Egyptian fighters in Islamic State intend to topple Egypt's U.S.-backed government and extend their caliphate to the biggest Arab nation.
"We will not be able to change the situation in Egypt from inside, but Egypt is to be opened from abroad," Younes, who asked that his last name be withheld, told Reuters in an interview conducted by Facebook.
Reuters reached Younes by contacting supporters of Islamic State on social media networks. Another Islamic State fighter identified him as a militant in the group. Location tags on his Facebook messages placed him in Syria.
Egypt is well aware of the risks posed by its citizens going abroad for jihadist causes and then returning. Egyptians who fought Soviet occupation troops in Afghanistan in the 1980s eventually took up holy war at home, training their weapons on Egyptian security forces and carrying out bombings.
The chances of Islamic State militants establishing a caliphate in Egypt are slim: the Egyptian state has crushed one militant group after another.
But the return of fighters with experience in Iraq and Syria could certainly bring more violence and complicate efforts to stabilise a country that has suffered from political turmoil, with two presidents toppled since 2011.
Egyptian security sources say they are closely monitoring militants fighting abroad and have lists of their names at airports to arrest them on arrival.
Younes was a 22-year-old student at Cairo's thousand-year-old centre of Islamic learning, Al-Azhar University, when he decided to join the world's most dangerous militant group.
Like al-Qaeda leader Ayman al-Zawahri, a former physician, he came from a wealthy family living in Maadi, an upscale, leafy Cairo suburb. He learned about Islam at a young age from his mother but mostly shared the interests of any other Egyptian youth: a love for soccer and martial arts like Kung Fu.
Younes took part in the street protests which ended 30 years of iron-fisted rule under President Hosni Mubarak in 2011. But he also rejected