Is there any text that proves that the Angel of Death complained to Allah Almighty about his mission, and that Allah Almighty promised him ease in it through means?

The Angel of Death is specifically tasked with taking the souls of people, and he is the chief of the angels entrusted with this mission. As the verses indicate, angels also undertake the taking of souls. Angels take the souls of disbelievers with violence and severity, striking their faces and backs, while they descend upon believers to give them glad tidings and strengthen them, taking their souls gently. One should be wary of unverified stories that have no basis in the Sunnah or the statements of the Salaf, for what is authentically reported is sufficient and adequate. It is enough of a lie for a person to narrate everything he hears.