Cruel? Nitrogen asphyxiation is probably one of the most painless, gentle ways to go.

Your trigger that you can’t breathe is a buildup of carbon dioxide. But as you can still exhale, you feel no panic. You just slowly drift unconscious and die. I’d take it over most causes of death.

Opinion 👆.

Fact: it's necessary to remove certain people who are prone to violence and incapable of rehabilitation. If you have such a problem with execution, then volunteer your time, money, and home to accommodate a violent psychopath with you forever.