This is a pretty easy achievement to get. But, there's a catch... COG TAGS MATTER!!! So, it will be easiest if you already have all 3 COG TAG achievements,
You don't need to have all 33 COG TAGS, but it might simplify things if you are marathoning the game. You'll just pick a comic, read it, and BING!!! Chievo Pop-O!! ...As long as you have all the COG TAGS for a single chapter, that is.
Let me walk you through this one:
All you need to do is get to the Comics by doing this:
Menu Screen > War Journal > Cog Tags
Now that you are looking at the comics, find 1 of the 5 comics, 1 for each act, that you have all COG TAGS for. They are as follows:
Unseen ( Act I ) : 12 COG TAGS
They Also Serve ( Act II ) : 6 COG TAGS
Unsaid ( ACT III ) : 6 COG TAGS
Promise Me ( ACT IV ) : 3 COG TAGS
Harper's Story ( ACT V ) : 6 COG TAGS
Pick one that you have every single COG TAG for; it literally does not matter which one you pick.
Now that you are looking a comic that you have all the pages for, hit
until the last page, tap
to zoom in, and scroll all the way to the bottom to where you can't scroll anymore.
Congratulations! Your achievvement should pop now.
If your achievement is not popping, it is for 1 or 2 reasons more than likely:
1. You don't have all the COG TAGS for that ACT, or...
2. You didn't hit
to look at every page before getting to the last one, tapping
to zoom in, and then SCROLLING ALL THE WAY DOWN TO WHERE YOU CAN'T SCROLL ANYMORE! This seems to the be the thing that is getting everybody the most.