I recently finished my Ochain and my strategy was to focus on Abyssea - Grauberg because it had an Ironclad (Iron Plates), Maere (Colorless Souls) and Azdaja (Azdaja's Horns). You could get all the materials to take your Ochain to level 90 in the same zone.
For IRON PLATES:
Head to
Conflux #8. Kill
Stygian Djinns to get a
Darkflame Arm. Kill
Sinister Seidels to get a
Bubbling Oil to spawn
Teekesselchen. In my experience, I got a
Teekesselchen Fragment ~80% of the time. Use the
Darkflame Arm and
Teekesselchen Fragment to spawn the
Ironclad Sunderer. You'll always get at least 1x
Iron Plate. Sometimes, you might even get 2x! All of these mobs/spawn points are very close to each other.
For COLORLESS SOULS:
T1 -
Air Elemental/
Dark Elmental: Spawns and wanders around the area south of
Conflux #3 and north of
Conflux #2. You'll get a feel for it and understand exactly where they'll always be once you do it a few times.
Goblins aggro sight.
Pugils aggro sound.
T2 -
Gamayun: Spawns and wanders around the area in-and-between where the
Sinister Seidels and
Monitors spawn.
Monitors aggro sound.
T3 -
Maere: Spawns and wanders around the area in-and-between where the
Sinister Seidels and
Monitors spawn.
Monitors aggro sound. He can and will use
Nightmare. It's nothing to worry about, but it will slow down how fast you can kill him only because you'll be forever asleep and eating Bio damage.
*** When hunting for Darkflame Arms and the T2/T3 Abyssite NM, watch for the Assailer Chariot. I know it's a bold new ilvl 119 world, but Homing Missile will still kill if you if you're derping around and not paying any attention whatsoever. They aggro something. I don't remember what. Just avoid them. ***
Absolutely get the Rhapsody KI ("
Rhapsody in Muave" from completing RoV 2-40) that forces the Abyssites to upgrade 100% of the time like Acey said. Unless you're a masochist, it is
imperative.
I always went as THF/DNC (lots of sneaking around to avoid sight/sound detecting mobs around the area where the T1-T3 Abyssite NM can spawn) and it was helpful. You can pretty much use whatever Trust combo you want as long as you can get some Haste II and Marches to help speed up the killing process.
It's just a time-consuming process. It's not really hard, though.
PS: Use this map. It is your friend.
Abyssea - Grauberg