Source: Bestiary 3, pg(s). 244
The merciless shinigamis seek to inflict quick, just deaths upon their quarries, do not seek to impose needless suffering, and do not take pleasure in their jobs. There are exceptions: some individual shinigamis, considered rogues by others, are either willing to listen to their victims' plight and grant clemency; or are willing to be bribed to let certain dastardly targets survive.
Resurrection sometimes falls under a shinigami's purview, if the subject's return perturbs social or natural order. However, some shinigamis use their mandate as an excuse to get rid of resurrected mortals when bribed.