Bound Hero Battle: Ephraim & Eirika

Nino can tank both mages and kill them with a fortify res buff if she doesnt have -hp IV. After that, the job is easy to deal with

Build:
Robin:
Weapon: Gronnwolf+
A: Fury 3
B: B Tomebreaker 3
C: Fortify Res 3
Support: Draw Back (Required)
Special: Bonfire
Seal: Atk +1 (Required)

Cordelia: (Must be neutral attack) (+Def -Hp)
Weapon: Brave Lance+
A: L&D 2 (Required)
B: Drag Back ( Hit and Run works)
C: None
Support: Reposition
Special: Galeforce (Required)
Seal: Quickened Pulse (Required)

Klein: (+Spd -Res)
Weapon: Brave Bow+
A: Death Blow 3
B: Quick Riposte 3
C: Hone Spd 3
Support: Draw Back
Special: Luna
Seal: Hardy Bearing

Olivia: Neutral (I did have Ruby Sword equipped though)

Introduction:
Due to the overwhelming amount of units with inflated stats, leaving them alive to encroach isn't a good idea. We have two brave users to handle the units' pitiful defenses, and Robin pulls her weight along the way.

Step 1:
So you'll want to start out by positioning your units accordingly. Robin will occupy the danger area above the breakable tile. Cordelia will position herself right beside the wall on the left. Klein will position himself right beside Cordelia, and Olivia will position herself right above Klein.

Step 2:
Green Cavalier should attack Robin. Blue Cavalier should have moved beside Green. Ephraim and Eirika should be directly in front of Robin. Red Cavalier should be in range of Cordelia, and Thief should be close by Cavalier.

Step 3:
What you want to do is get Robin the hell out of there. Move down two spaces, if Olivia is where she should be, use Draw Back on her and get Robin out of range of Ephraim. Kill Green Cavalier with Klein, dance on him, then kill Blue Cavalier. This next step is essential. Cordelia should be neutral attack, no merge should give her even 1 attack, and she should have L&D 2. If you meet these requirements, Cordelia should get a Galeforce proc after single combat with Red Cavalier. Olivia should still be in the position she started in, and thus after killing the Red Cavalier, Cordelia shouldn't move from Drag Back. Move in and kill Thief.

Step 4:
Ephraim and Eirika move in. Robin should be at 1 with her Special. Move down two to get in range to attack Ephraim. Shortly after that, dance on her (make sure not to be in Eirika's range) and move towards Cordelia and Klein before attacking again. attack with a Bonfire proc, and Ephraim should be dead. Reposition Robin out of there.

Step 5: Eirika moves in. Brave bow her, then kill with Cordelia.

Notes: Dancer is required. Enemy may move differently depending on who you use though. I attempted to use another green mage, but the Red Cavalier would run straight up to attack said mage. He moves towards the others instead because of Robin having the Gronnwolf tome. If you can kill the Red Cavalier, get a Galeforce proc and live, as well as kill Eirika, any Brave Galeforce user can take Cordelia's job. Enemy may move differently though. Finally any Brave bow user can work.

Simply: Lyn to the rescue, Eldigan not short behind!

Neutral Brave Lyn needs Brave Bow or Brave Bow+, and HP seal.

Eldigan mostly for Hone Cavalry, but if you dont have Brave Bow+ he will need to do some cleaning (can be repalced by any red riders with 50+ atk or any blue rider, as long as it has hone cavalry)

2x Dancer/Singer, any. But if you have only Brave Bow on Lyn (like me, coz im not big fan of that build) you need spur atk on one of them.

Gameplay:

Just destroy the wall with Lyn(from spot closest to noname enemies) in first turn and place one of dancers there. Put cavalier next to Lyn and second dancer so she will be able to Dance/Sing Lyn, after Lyn jumps on the thief.

In next turn just go and kill thief, then dance Lyn with the one of the dancers (the one with spur if you dont have BB+) and melt blue mage, then dance her again and melt green mage. Let red cavalier hit you, and kill him in next turn as payback.

Then just sweep the rest, if you have BB+ there is no trick to it, if not you need to fall back (i got separated from one of my dancers, pivot!) and then in next turn severely injure Eirika, dance Lyn and injure Ephraim, then finish Ephraim with your second rider, dance him with second dancer and finish off Eirika.

Start by killing dagger with Lyn (brave bow), then sing for her, and use her to reposition Azura out of danger (previously broke the wall so Azura can go there). Julia swaps with Lyn and on enemy turn kills blue mage (Julia is my summoner support, which might be necessary for the ko depending on ivs). Next turn Camus kills the red cavalry, other units pull him out of danger, and Julia goes in range of green mage. Next turn Camus finishes off green mage. Azura kills Eirika (Swordbreaker on Azura so she doubles). Julia attacks Ephraim to weaken him, and Lyn finishes him off.

My team specifics. No Ally or Summoner supports:

Xander - Neutral.
Attack+3, QR2, Hone Cavalry.
Siegfried, Reposition, Bonfire

Brave Lyn - Neutral
Swift Sparrow 2, Sacae's Blessing, Atk Smoke 3
Mulagir, Reposition, Draconia Aura

Ephraim. 5*+1. +Atk/-Def
Siegmund, Reposition, Moonbow
Defense+3, QR3, Hone Speed

Nino 5*+1. +Spd/-HP
Gronnblade+. Draw back, Moonbow.
Fury 3, Desperation 3, Hone Atk 3

================Turn 1================
Player phase:

Move everyone so that:
-Lyn is up one, right two from the red cav.
-Xander is to her right
-Nino is above Xander
-Ephraim is to the right of Nino. Have Ephraim break the block

Enemy phase: No movement

================Turn 2================
Player phase
-Honed cav Lyn takes out the blue mage
-Move Xander to Lyn's right and have him reposition Lyn so that she's above Nino.
-Have Nino draw back Lyn.
-Xander should be in the range of the thief and green mage. Everyone else is safe
End turn.

Enemy phase:
-Red cav should move up to rally the thief.
-Thief should hit xander for 0 dmg and die.
-Green mage will hit xander and die.
-Eirika moves diagonally down right.
-Enemy!Ephraim moves diagonally down left.

================Turn 3================
Player Phase
-Move Ephraim up one spot so that he's in Eirika's range.
-Move Nino under Ephraim for buffs.
-Move Lyn over two to attack the red cav.
-Move Xander to hit/KO the red cav from Lyn's left (/from below the red cav). Make sure Xander is not in enemy!Ephraim's range.

Enemy phase:
-Eirika will attack Ephraim and die.
-Enemy!Ephraim moves closer

================Turn 4================
Player Phase
-Have Lyn Reposition Nino so that Nino is closer to enemy!Ephraim.
-Nino attacks and KOs enemy!Ephraim.
-You win