Re: Shooter games
"What about Hindus, where they're religiously commanded not to kill even the tiniest fly [...]"
The modern ones seem fairly keen on killing those who are not Hindus - or those of the Hindu "Dalat" lowest caste who breach the Hindu system's job/rank preservation rules.
Jainism is the Indian religion whose monks wear masks to avoid the possibility of killing a fly. There are various sub-sects from many schisms - but their central core is non-violence.
Buddhists are also supposed to be non-violent - but recent events in Myanmar have definitely contradicted that. At a monastery in Macau they have a public restaurant that follows their generally vegetarian principles. It was a surprise to find fried oysters on the menu. Apparently that is where they draw the line at "sentient" life.
The nominally Christian*** Quakers are a religion whose members have proved many times to be conscientious objectors to war - at great personal cost. They often undertook some of the most dangerous unarmed jobs in support of the wounded on the battlefield.
***Many Christian organised religious groups dispute that the Quakers are Christian. Their philosophy is non-hierarchical - and all about personal conscience.