Yesterday I did the first post-time skip Azure Moon chapter, Reunion at Dawn on Maddening.
HO. LY. SHIT.
That was by far the most brutal thing so far, and I'm so glad I prepared for it ahead of time. I had Battalion Vantage, Battalion Wrath, Swordbreaker, and Lance Prowess on Dimitri with Killer Lance+ (couldn't get him to Lance Crit +10 in time - my fault on that), and Byleth on a Wyvern, and it took me several restarts to make it work. I tried putting Dimitri in the bush right next to his starting position, but he either got eventually swarmed (archers were the problem), or they decided to not all go after him and go for Annette and Mercedes instead. Also, that was some cruel shit giving me my squishy wizards by themselves and withholding Ingrid, Felix and Sylvain, any of which would have been SUPER useful in that initial stage, instead of fucking Gilbert (ended up just having him stay put and not aggro anybody, which left most of the northern troops stationary until I was ready to engage with them, and Ashe could fly out of there on his own). I had Dimitri go to the next closest bushes and stay there, and did hit and run tactics with Byleth on the archers (Lure gambit was great for me), until they were gone, after which Feral God Dimitri couldn't be touched. Ashe had Impregnable Wall, which was a lifesaver a few times, especially since Ashe himself could just retreat after using it to help somebody.
Sword of the Creator did a lot of good work there, especially on those archers. I don't like using it cause of the Rest to restore situation, but it saved me a few times by turning messes into OHKOs.
After the initial enemy rush, it was a lot more manageable, especially with Ingrid and Felix coming back. Marianne is my dancer, so that was missing, and Gilbert was useless, but other than that everyone had their part to play, other than maybe Sylvain, just because of his late entrance.
That was definitely grueling and very dicey, though. If you just walked into that without preparing or without an earlier back up save, that might be game-ending, or at least cost you some units if you're on Classic.