Those blasted ruffians are at it again and Anna is the point of their focus. But wait...something's different.
Anna the Merchant – The Twins' Hideout
Objective: Rout the enemy
Enemies: Ruffian Barbarian x 9 Ruffian Mymridon x 4 Ruffian Archer x 4 Ruffian Mage x 7 Ruffian Thief x 1 Commander – Vincent – Berserker x 1
Bring Gaius or another Thief to this fight. There are a ton of doors and several Treasure Chests that you can't possibly have enough Keys to unlock. Even if you did, you could just use a Thief to pick all the locks for free. A Thief will be invaluable to you during this fight, so keep him/her alive at all costs.
And just in case you're not sure how to pick locks, simply walk up to the door or Chest in question and select either the Door or Chest option that pops up when standing near either object.
Also, it would be wise to avoid bringing any air-mounted units (Pegasus Knights, Wyvern Riders, etc...) to this fight. There are four Archers on the field and two of the Mages use wind magic that will stop a Pegasus Knight like a sailboat on a calm summer afternoon.
Your party will start out in a scattered position with enemies directly in front of nearly every one of your party members. Suffice to say, a defensive position is pretty impractical during this fight. Go for a full-on assault. Just be smart about it and keep your Healers out of harm's way.
Really, the toughest part of this battle is getting all of the Treasure Chests before defeating all of the enemy forces. Most of the enemies, Vincent included, will likely kill themselves trying to take you out. If you're not fast enough on getting the Treasure Chests, there's a good chance you'll miss out because of these poor, pitiful soldiers repeatedly throwing themselves at your swords until Death brings them respite.
Completing this battle will reward you with a new party member named Anna, who you may remember from Paralogue 2. She's a Trickster, which basically means she's a Thief, so she can do all of the lock-picking that Gaius and other Thieves can do.
End of Battle