u/dowonlee20

When it comes to bosses they must die but you can rationalize the two out of three as 'Adam' killing them not you. It was 'Adam' who stabbed Barrett to death so you can say it was the cutscenes which did it therefore it doesn't count as your kill. Also for Namir you can say the punch by 'Adam' in the cutscene is what killed him so that is not your kill also. Fedorova is where there is no excuse it doesn't matter wether you use lethal or non-lethal because when the cutscene plays after her health reaches 0 she bleeds to death. However there is one way to defeat her without you being responsible for health going to 0. The only way to do that is you can attack her as much as you want with any weapon but she must electrocute herself to 0 hp. The game doesn't count you killing Fedorova as non-lethal but you know better. Don't lie to yourself and make sure Fedorova is responsible for her own demise for a legitimate non-lethal run.

One might think non-lethal is more difficult because players would need to constantly sneak around to knock out an enemy. But non-lethal becomes extremely easy when you upgrade Micro-Assembler and TESLA to the max level. Using Micro-Assembler it is possible to get many Crafting parts to make TESLA ammo and you could basically auto target enemies and shock them to unconscious. In fact shooting the enemies with bullets is more difficult and time consuming.