Hi all! If anyone could help, I would really, really appreciate some help in finding two fanfictions!
The fanfictions were posted to Fanfiction.Net anytime from 2009/10 to 2019. They were Attack on Titan fanfics and were both at least 20 chapters long each.
The first fanfic basically has Eren, Annie, Bertholdt, Reiner and Ymir escape the three walls and head to a base across the sea. I feel like the base was descibed to look crystallised and that the five of them had to swim to get into the base. The latter 4 shifters are from different militaries (Not Marleyan, but militaries like the US, Egypt, etc) and could've time travelled to have that happen, but I'm not sure if I'm misremembering. Ymir could've been from the Egyptian army if that helps. They re-enter the walls, head to the Yeager household and go down to Grisha's basement. They find, in a box or coffin of some sort, Marcel or Marco (I believe it was Marcel, but could've been Marco) and he's deteriorated some, but is alive and given something to make him more 'normal'. The shifters had two large dogs that were, I believe, described as 'Hellhounds'. It could've started as one that trope where Eren would be betrayed by the Survey Corps as a whole (not the main characters though, I don't think) and the five of the shifters escaped.
The second fanfic that I'm looking for had the main survey corps characters travelling underground using tunnels that were attached to The Walls or Grisha's basement (more likely the walls) in some way. From what I remember, the characters make it to the outside of Wall Rose (so, technically in the Wall Maria area) and Eren, Mikasa, Armin and Levi are seperated from the others. I think Levi was sick/injured after the tunnels, so the trio tries looking for a place to stay, and stumble upon Mikasa's old house (before she moved in with the Yeager's). If I remember correctly, either Hanji or Sasha become a titan (Jaw titan maybe) and that Kenny and his squad are killing/hunting people and that's why the Survey Corps left. It had two parts (original and sequel). I feel as though it could've been titled something similar to 'Outmanoeuvred' but I don't believe it is that exactly, as I think there is another fanfic with that name, but it is not the one i'm looking for.
I'm sorry if this is not a lot of info to go off, but thanks in advance If you find it!! Please ping me or DM me if you know of it! Thank you!!