As you report back after having finished that third Challenge Quest, a samurai will tell you that Navarre has gone missing in Naraku. Of course, Navarre is a prideful piece of sh-- I mean snob, and would be willing to choose death over ... being rescued by a Casualry, so you have to be quiet about it publicly.
Anyways, prepare for the journey (be sure to rest in the Barracks and grab some Detox Solutions!) and enter Naraku.
Local Demon Bestiary
|Grudge Horde||5||No||Horde||Fire, Light|
|Samurai Zombie||4||No||Undead||Fire, Light|
|Samurai Zombie||5||No||Undead||Fire, Light|
|Slime||2||Yes||Foul||Physical, Ice, Fire, Electric, Force, Light|
|Tengata Manu||2||Yes||Flight||Gun, Electric|
Begin your journey by heading to the 3rd Stratum. To get there, return to where you fought the Orthrus earlier and look to the south. There should be two westbound paths; break the wormwood off the northern of the two and go along down to the next floor.
As you arrive, you'll notice a hooded man - one who was absent if you came before. He suddenly summons two Naga!
Boss: Naga x2
|10||Snake||Fire||Dark, Light, Electric||Ice|
As you could probably guess, you get pre-emptively attacked by the hooded man's Nagas. They have the ability to further increase their Strength beyond that which is already the most powerful you've seen insofar - in fact, they tend to use that initially and shoot you with an attack.
This can deal 50 ~ 80 damage pretty easily, which often spells one-hit-kill for you. You probably also don't have any Fire-based attacks unless you've been using Demon Fusion, although they're really weak against that - easily 150+ damage per hit.
Otherwise, the main thing you can do is concentrate your offense on just one of the Nagas at a time. They can be put to sleep if you have Dream Fist (learned by Mokoi), although it's not common.
After the battle, head south, then read the sign. You'll notice that there's poison to be fared against later on, which is true. If you didn't get the Detox Solutions as I previous recommended, go back and get them. Go through the door nearby, then attack the wormwood you can see in front of you.
Behind it is a hole near the ground. Press Down then A to go into it. Once inside, to the right is a Detox Solution .
Return outside and head east. As you pass the torches, you'll suddenly meet Walter, who's been injured, who reveals something important that you probably already knew about Navarre. Further to the east is a hole near the wall base, although it yields nothing.
So you'll have to go north. Through that purple water. Crap. Just beeline north to the fork and head west. Break down the wormwood there and you'll find a chest containing a Dies Irae ! Equip it now; the relatively low hit rate is made up for by an over 50% boost in general power.
Turn around and finish cross the poison via the other branch of the fork. On the other side, cure yourself of the poison with an item or skill, and probably heal some HP as well. From there, head east at the north/east fork, then north at the next fork.
Crawl up the ledge partway across and proceed along to the chest, which contains some HP-healing Medicine . Now beeline your way southward and go through the door.
Continue south and break down the wormwood wall on the way, although it just makes a shortcut to the start of the poison-water pit. Go back north and through the door, then west, then north at the fork. As you go along, you'll again meet the hooded man, who decides to teach you another "lesson".
|10||Jaki||Fire, Electric||Dark, Light, Force||Ice|
This fight will be much easier than the previous one. Firstly, this enemy is unable to attack multiple times per turn; it's alone; and has more (common) weaknesses. There's not much to mention about this other than hack-'n'-slash with weakness-abusing attacks, but do try to keep your party's HP high initially.
It's not too unlikely that you can combo around Agi and Zio to finish this thing before it gets a chance. But...
Boss: DDS Horde
|10||Horde||Electric||Dark, Light, Force||Ice|
Soon after having beaten the Wendigo, the man summons a horde of them as reinforcements! Jonathan soon arrives, alongside Isabeau - which startles the hooded man, as it is two Luxurors allying a Casualry.
So, in other words, basically the previous battle. It still remains pretty easy, although your enemy is now twice as dangerous due to multiple turns per turn. Of course, if you have enough people with Zio - and you should at this point - you can cyclically kill this thing before it gets a turn.
Be wary, though, if your allies are weak to Ice - this enemy often opens with a power-boosting move before a party-wide Ice attack.
After the battle, the hooded man is shocked at the failure of his plan to put the Casualries in their place. While Jonathan and Isabeau elaborate on why they helped Flynn, Walter walks in and Jonathan catches him up. Meanwhile, we decide to head further in, leaving the hooded man to be punished another day.
He gladly flees, leaving a trail of urine behind. The three others accompany you to Navarre. As you progress along the path, another person arrives in samurai armor. He appears rather suspicious, no? Continue along to what is indeed a funny-looking wall and enter, despite the presence within.