inhumanitarian 

One who repeatedly demonstrates an outright disregard for the needs or rights of others, often showing marked cruelty.

An inhumanitarian historically does not possess empathy or compassion which can lead to mass suffering when they are in a position of power.

inhumanitarian by Dr Bunnygirl June 20, 2018

Inhumanitarian 

Someone that is a horrible person, even when nobody is looking.

The inhumanitarian is always doing the most inhuman things you can imagine to people.

Inhumanitarian by The Original Agahnim November 8, 2021