In this area, you can speak with a Quicksilver in battle (requires Demolingual) to get a Challenge Quest. This one is a long one, but rewards a useful St Incense x5 ! It concerns Isis, an Egyptian goddess, who wants the coffins of her husband Osiris.
It is supposed to be dropped all of the way back in Naraku, on the second stratum. If you want to do this once received, head along to the underground district back in Ueno, use the Terminal to go to Mikado, then enter and go along from there.
On the 2nd Stratum, go south and into the first door to the east, as usual. Then go into the room that is normally empty to the north. To find the desired coffin, head down to the 4th Stratum. Go down the ladders and cross the bridge to the south.
Go through/past the waterfall to the south and head along to the end of the path to find the coffin. (Once taken, all you can use are "Run" and "Next" in battle. The coffin is also damage when Flynn is.)
As you go along, keep aware of that red bird-like demon that gives chase: Seth!
|45||Vile||Ice||Light||Electric, Force, Dark|
Ideally, you won't want to combat this dude. His basic attack will shave off about 60 points of your HP around Level 19, and there is the fact that you can't have Flynn fight him or your other Samurai allies. That's what he'll mostly use.
The fight is far from impossible, though - I got by with just two demons able to use Bufu and no items. The main key is to have someone able to use Media, preferably two, and maybe even someone able to use items. But, while it's difficult, it's still doable with plenty of Ice attacks.
Keep in mind that Seth can be battled multiple times and often loves to appear in your darn face. Keep a watchful eye as you return to Isis on the 2nd Stratum to get your well-earned five Strength Incenses .