There are some missable ones such as the one after you defeat traffiking 3 times. Before proceeding you'll want to take the right and you'll find one missable ANGEL along with 4 hosts' piles and the last 3 are also missable because you need to kill them before killing the twin sisters, otherwise the ANGELS will explode upon defeating the sisters but it'll not count towards the achievement.
You can replay the chapters you missed something after you beat the game but in order to unlock this achievement case you forget any ANGEL make sure you play on the difficulty you first started killing them otherwise IT'LL NOT WORK.
My tracker was at 95 or 96% when I first finished the game. I tried to get the remaining ANGELS on New Game+ and it didn't work because I first started on normal and New Game+ is set on Hard. Then I tried starting a new game on easy to speed things up making sure I didn't leave any ANGEL behind and by the end of the game no achievement. I replayed ALL the chapters where there's ANGELS to destroy triple checking if I actually killed them all but again nothing. I tried starting a new game one more time on easy making the most absolute sure I destroyed ALL of them, story related and optional ones but still no achievement.
Then I figured maybe I had to replay the chapters on the same difficulty I first started in order to work and that's exactly what I was doing wrong. Once I started playing on normal and destroyed the last remaining angel the achievement unlocked.
Here's a visual aid in case you're struggling finding them all: