-Pre-Chapter Shopping: Forge the Flux with +4 Mt, +5 Hit (assuming 14 Mag); if Risen are preventing a Flux from being purchased, then forge a Thunder with +12 Crit.
-Tonics: Chrom (Str), Robin (Def)
First Wave — Opening Problem Enemies (North side)
-Steel Axe Barb (Aegis+, Pass)
-Thief (Pavise+, Counter)
-There is also an Archer, but even with Aegis+, Fred can pick him off on the next turn. Even if the Archer and Thief both have Luna+, as long as the Barb dies and Robin’s counterattack will OHKO the Thief, she shouldn’t die.
-Fred with Lances A and Virion C can one-shot Thieves with the Silver Lance if they don’t have Pavise+.
-Against the Barb, one dual strike when doubling can be considered as reasonable, if somewhat risky, expectation (should be around 55% chance at this point; meaning a 20.25% chance of failure). While Solidarity-Rapier Chrom has a non-trivial chance of crit, it also can’t be counted on. Barb has 17 Avoid. Base Chrom can only hit for 8 (10 with Tonic) with the Rapier. However, with the Renown Glass Sword, he can do 14 (16 with Tonic).
-Robin with the average 14 Mag with B Tomes and Thunder, Robin will have 18 Attack. Average Skl and Luk with net Robin +25 hit. Chrom support adds +10, another +2 from pairup bonus, bringing the total to 37.
-If Chrom hits with the Glass Sword at any point, Robin needs 2×11 damage to one-round.
-A +4mt/+5hit Flux forge will let Robin finish him off (technically overkill, but need a +2mt Flux minimum and the Glass Sword won’t last for further Barbs and even if it does, want to save it for C5). Need to be careful about this tome with Counter, though. Also note that Flux’s hit is rather poor, so the +5 hit pushes Robin into ~95 displayed hit, which gives are 99.55% true hit. Although 90 displayed is 98.10%, only 1.5% behind. Depending on funds situation, could possibly forgo the hit bonus to save 270 gold.
-Base Fred with Lances A and Viron C will have 21 Attack against the Thief with a Javelin. Against Pavise+, this will do 9. Robin then just needs 20 Attack to one-shot him and prevent Counter. This falls to 17 against the Barb, where 13 damage can be enough to finish him off if Robin and Chrom couldn’t. However, there cannot be a problem Thief for Fred to be available for this backup strat.
Second Wave
-Robin can get kill the forwardmost, which puts the a melee enemy in range of her.
-If that melee enemy has Counter, he can be baited into Short Axing Sully at range (she can survive a Luna+ hit so long as she has a sword equipped). Unpaired Fred can also be used to bait.
Treasure
-If both melee Barbs along Thief escape route have Counter, clearing it out in order to ambush the Thieves can be a bit tricky. There are a couple ways to handle this.
-Route A: Go through middle. Unpaired Fred can bait lower Barb without provoking Archer by going one up from the Woods tile by the 1×2 wall. Robin can then nuke the top Barb. This will, however, draw fire from 2 Archers and a Short Axe Barb. The lower Thief will also aggro (non-Pavise+ can be one-shot by Fred, non-Counter can just be tanked). Killer Lance Thief will swing down, but not initiate attacks. If body blocked without Pass, will still fixate on the bottom escape tile and take the long way around.
-Route B: Go around back through the pillar room. There will be a lot of enemies in range at various points, though. While they’re mostly 2-range, this variation gambles on more consecutive Robin dodges. This strat is also not a good idea if the two pillar room Barbs have Counter.
-Far Thieves will also choose to pick a fight instead of moving closer to the Chests.
-Once the one Thief has the Killer Lance, he will ignore combat to leave off the south side of the map.
Nabbing Donnel
-Trapping the armoury Archer and having Donnel poke solo is enough EXP to recruit him. If the Archer has Pass, the tight confines of the room allow people to just plain body block him from getting out. Put unequipped Fred next to Donnel to have him soak the hits while body blocking. This can be used as an opportunity to get Lissa a bit of EXP too (don’t go too crazy, as those Heals are valuable for later chapters and the budget is tight).
-Donnel’s Attack is so sad unpaired that he doesn’t really care about Counter. He’ll need to hop out once for a healing if the Archer does have it, though.