Renald Luzier, the sole surviving cartoonist of the French publication Charlie Hebdo has decided to leave the newspaper, saying it is "torture" being the only cartoonist left and that he needs time to "rebuild himself."

Luzier, who goes by the pen name Luz told French newspaper Liberation that work at Charlie Hebdo had sadly become "too much to bear."

"There was hardly anyone left to draw," he said. "I found myself doing three front pages out of four. Each issue is torture, because the others are no longer there."

The publication was the victim of a terrorist attack in January after it portrayed the Prophet Muhammad. Two brothers linked to Al Qaeda opened fire on the staff and killed 12 individuals, including Charlie Hebdo's editor and three cartoonists.

Luz has worked with the paper since 1992, and created their first front cover image following the attack. It showed Muhammad weeping and saying, "All is forgiven." The cartoon prophet even held up a sign that said, "Je suis Charlie," which became their slogan after the killings.

The cartoonist said that his decision to resign was very personal, and that he needed to regain control of his life. His resignation will take effect from September this year.

"Spending sleepless nights summoning the dead, wondering what Charb, Cabu, Honore, Tignous would have done is exhausting," Luz shared.

Following Luz, another newspaper employee might be leaving soon as well. Zineb El Rhazoui, a French-Moroccan columnist has received several death threats because of her articles that take a jab at Islamic extremism.

Not only that, but Rhazoui's husband even lost his job because of her articles and has received his fair share of death threats too.

"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."