I was going for the "It Itches" achievement, but the rash was actually cured like any other injury when I returned to the bridge lol. I think that's a bug because other playthroughs I've had to go to the chapel and pray to remove it. But when I'm actually trying to keep it, it is cured by accident/a bug. Classic owlcat.
I also don't have the "kill 3 people with rend vision" achievement despite doing that several times this playthrough and my previous playthrough, with both the player character and Cassia, so that one is also bugged.
I also don't have the "be self sufficient in the blood investigation" despite doing every stage myself and never skipping any of the stages by delegating it to Jocasta. I've done the dlc three times now without delegating anything and not getting the achievement, which leads me to believe you can't let any one do literally anything. So you can't let Pasqal convince the tech priest to give you access to the computer, you can't let the enforcer conduct the autopsy, you can't let Jocasta kill the cultist, etc. I think you have to do literally everything, even dialogue, yourself.
One other achievement that has been elusive is to visit every optional location. I've played the game 4 times and I've gone to all the secret locations I know of like Incendia's stasis pod and the drukhari stash on the ice turret planet and the halo device noble and a ton of others. I really am at a loss for what I'm missing, I suppose I'll have to look that up online.
I really don't want to get the two chaos achievements. There's one for beating the game as conviction chaos and one for surrendering Euphrates to chaos. A whole playthrough of being a retard just for some achievements.
Biting 7 people in one turn with the mastiff will also take some figuring out. I've only bit like 4 people before running out of ap so there must be a trick to it.
I'm so close, I'm excited to 100% this game.