So since I finished the main game and both of Daud's DLC, all are amazing, I am gonna go back and play again but I think this time I want to go a little more stealth then I did on my first run..well more so low chaos. I will however probably kill my targets this time instead of the nonlethal way. So I ask you fellow Dishonored players what powers should I invest in the most for this type of playthrough? I know the See through walls one (forgot the name) is a must..but I am not sure which others to choose. I just got out of the prison (did that all nonlethal and without alerting anyone) and I got my Outsider mark and have gotten the see through walls skill and vitality one but again not sure what others I should invest in..or how and when to properly use them.

Thanks!