Renald Luzier, the sole Charlie Hebdo cartoonist to survive the brutal massacre of the magazine's staff by Islamic extremists, is leaving the publication in an attempt to "rebuild himself."

On Tuesday, Luzier, who draws under the pen name Luz, said in an interview with French newspaper Liberation that continuing to work at Charlie Hebdo had become "too much to bear."

"There was hardly anyone left to draw," he said in the interview published on the newspaper's website late Monday. "I found myself doing three front pages out of four."

Four of those murdered were the editor and cartoonists for the satirical publication, known for its controversial depictions of religious figures, including Muhammad, the prophet of Islam. The attackers, two brothers linked to the Al Qaeda in the Arabian Peninsula terror group, reportedly yelled "We have avenged the prophet Muhammad" and "Allah is Great" in Arabic, reports the BBC.

"[Each issue is] torture, because the others are no longer there," the cartoonist explained.

Luzier, who has worked for the magazine since 1992, is credited with drawing the French satirical magazine's first front cover image following the deadly terror attack showing the Prophet Mohammed weeping and saying "All is forgiven." The cartoon prophet held a sign saying "Je suis Charlie," the slogan of those who stood up for the magazine after the killings.

The cartoonist said that his decision to resign, which will take effect in September, was "very personal" and that he wanted "to rebuild myself, to regain control of my life."

"Spending sleepless nights summoning the dead, wondering what Charb, Cabu, Honore, Tignous would have done is exhausting," Luzier said, referring to his colleagues who were among those killed.

Meanwhile, another employee of the newspaper may be forced to leave soon. Zineb El Rhazoui, a French-Moroccan columnist at the magazine, who had received death threats over her articles attacking Islamic extremism, was last week summoned by the management for a preliminary dismissal hearing.

France 24 reports that since the January attack, Rhazoui has been the leading voice for the newspaper on the Islamic front, and was surprised when she received a summons from the newspaper's management.

"I am shocked and appalled that a management that has received so much support after the January attacks could show so little support for one of its employees, who is under pressure like everyone in the team and has faced threats," Rhazoui was quoted as saying.

She added that in light of her articles on radical Islam, even her husband has lost his employment and received threats from upset Muslims.

"My husband lost his job and had to leave Morocco because the jihadists revealed his workplace," she explained. "I am under threat and having to live with friends or in a hotel and the management is thinking of firing me. Bravo Charlie."

RT notes that the newspaper is now owned 40 percent by the family of former editor Charb, one of the victims of the January attack, 40 percent by new editor Riss, who survived it, and 20 percent by financial director Eric Portheault.

The owners said a special commission will determine the fate of the donations.