Unlike other entries in the series, Assassin's Creed Shadows isn't all about sneaking around and killing enemies unseen, but stealth is still a big part of the experience, especially if you like using Naoe a lot. While Yasuke can hold his own in a fight against multiple enemies, the shinobi from Iga is almost always at a disadvantage in open combat, as her toolkit is more geared towards stealth gameplay and taking down enemies without being discovered.
Unless you are equipping the best possible gear at any given time, however, Naoe is not always able to kill enemies in a single strike by approaching them silently and using the Assassination ability. Whether it's due to an enemy's high health or armor, there will be times when an Assassination attempt will result in open combat, which can be a massive issue for the young shinobi.

If you want to improve Assassin's Creed Shadows' stealth gameplay features without having to constantly hunt down the best possible gear, there's an easy way to make sure both Naoe and Yasuke will always perform lethal Assassinations. At any time during the game, enter the Options menu and access the Gameplay tab. Here, pick the Difficulty Tuning option, where you can set the Combat Difficulty and the Stealth Difficulty and turn on Guaranteed Assassinations. By turning on this option, all your successful Assassinations will automatically kill the target, regardless of the remaining health.
While turning on Guaranteed Assassination in Assassin's Creed Shadows may feel a bit like cheating for some, it is a massive game changer for stealth gameplay, as without it, the Assassination ability leaves something to be desired most of the time. With it on, however, you don't have to worry about anything else other than sneaking around and being a proper, lethal assassin!