“For Egypt to become fine means taking out el-Sisi,” he argued. “I don’t want the army or the Muslim Brothers to take over, but a citizen, someone from the people.”

Since early September, Mr. Ali has released more than 50 videos online, all of which he says were made in Spain, and ranging in length from less than a minute to more than half an hour.

Mr. Ali, who spoke in the interview, as he does in his videos, in a street-smart Arabic slang, has detailed incidents of corruption and mismanagement of state funds, which he said was conducted under the close watch of Mr. el-Sisi and his closest circles within the army.

He said Mr. el-Sisi has spent millions of dollars on building new presidential palaces at a time when many Egyptians are struggling to cover their basic needs under austerity measures pushed by his government.

“I think that what Mohamed Ali has shown is the limitations on President Sisi’s repressive measures and how they can backfire,” said Hussein Baoumi, an Egypt researcher for Amnesty International. “The problem for the authorities is that there is no easy way to refute his claims.”

As millions of people tuned in, Mr. Ali dedicated some of his videos to criticizing entire speeches made by Mr. el-Sisi, who has publicly called Mr. Ali’s claims “lies and slander.”

Mr. Ali soon began rallying people to protest against Mr. el-Sisi, even releasing a video in which he discusses what the system of government should be after his ouster.