You can finish Dishonored 2 without killing anyone

Just like its predecessor, Dishonored 2 can be finished without the need to kill anyone.

Dishonored 2's achievements include a non lethal completion award but you'll have to kill for 100%

Clean Hands, Dishonored Wiki

Dishonored: Death of the Outsider review – short, but strong on atmosphere, Games

Dishonored: 10 Tips For Playing Non-Lethal And Getting Low Chaos

Chaos, Dishonored Wiki

Mission 1 - A Long Day in Dunwall - Dishonored 2 Guide - IGN

Dishonored: Death of the Outsider review—no gods, no kings

Dishonored 2 - Wikipedia

You can do a pacifist playthrough in Dishonored