MY GOD that scumbag hammer bandit in chapter 3 LUNA+. HE HAS 100% accuracy cus of the broken skill. Then the counter Knights.. How brutal.
I was able to beat this map, and it's smooth sailing from here. Since start chapter 4 I can abuse brave weapons and dlc's.
So technically chapter 3 and 2 are the hardest chapters in the game.
I am considering not using DLC's/wifi for this thing though. That's just suicide though huh.
For chapter 2, I found getting that Iron Axe on FRED to be a life saver. Take out the ax guys with your bronze sword + Support C Robin (plus str/speed), and then somehow... get the axe and proceed to solo the rest of the map.
Chapter 3, I talked to Kel then pair up, then have him move over to FRED and switch into Chrom then Transfer so that kel gets on fred. Run over to the archer and one shot one. I placed chrom plus a cav in a spot where the Lance guy can hit Chrom equipping rapier. Then the armor knight smacks Fred, and dies. Then my two mages pot shot the lancer safely. Then the archer, then i finish off with Chrom. Fred one shots the other archer.
This is where luck is critical. Fred at this point is a beast and cannot die. But he does die to Counter. and that's about it. So depending on your luck you can do it. I send Fred back over and he was able to kill everything. The second part is very dependent on that hammer bandit. If he has 100% accuracy it's extremely hard. Just kite him accordingly and you'll be fine sine FRED and Kel is a godlike combo. I was extremely unlucky when I beat it though so it's doable regardless. The knights all had counter. So I had to use Javelins to weaken them. Then take 15 damage to myself the next turn when I enemy phase hit the knight.
Once you down hammer knight, it's over. The boss is a joke. :) GOOD LUCK