If you’re working in a microbiology lab, you’ll regularly use an autoclave and ethanol to kill microbes. Occasionally, you’ll even need to dispose of old cultivations by autoclaving them. That could be something like 10^7 cfu/ml*1000 ml = 10^10 living cells brutally roasted to death.
A medical license too (although some specialize in roles that have more / less of the killing)
It also allows you to advise others on how to kill specific entities, or to sign off on tools used for intense killing (prescriptions)
True, if you count virus and bacteria then doctors are probably mass murders.
Viruses are debatably not alive and may not count (depending on what you define as alive).
If you’re working in a microbiology lab, you’ll regularly use an autoclave and ethanol to kill microbes. Occasionally, you’ll even need to dispose of old cultivations by autoclaving them. That could be something like 10^7 cfu/ml*1000 ml = 10^10 living cells brutally roasted to death.