SE is one of the easier sections, only 4 floors, but each floor's mobs have specific damage/weapon resistance. Here's the wiki info for the lazy peeps:
First Floor *
Enemies: Metalloid Amoeba x8 (Slimes)
o Immune or highly resistant to Lullaby.
o About 7500 HP
o About 3/8 drop an Ancient Beastcoin.
*
Boss*: Ghost Clot (Slime)
o About 10,000 HP
* Monsters on this floor are immune to blunt damage.*
o Rush, Flaming Crush, Mountain Buster and Chaotic Strike do no damage.
o Also, Avatars' normal melee attacks (Garuda, Shiva, Leviathan, and Ifrit confirmed) do no damage.
o A MNK can equip Vampiric Claws to deal damage to the Amoebas. Hand-to-Hand weaponskills, Kick Attacks and Counters will still do 0 damage though.
o The Warrior ability Tomahawk will allow blunt damage, however it is still quite low compared to that which you would get on monsters occupying the other floors.
* The chests drop directly from the Amoebas.
* The Items chest has 4 Ancient Beastcoins and 0-2 AF+1 items (RDM, THF, SMN, BRD, DRK, RNG, NIN, COR, DNC)
Second Floor *
Enemies: Adamantshell x8 (Crabs)
o About 8500 HP
o About 4/8 drop an Ancient Beastcoin.
o Linking.
o Immune or highly resistant to light sleep.
*
Boss*: Tieholtsodi (Sea Monk)
o About 10,000 HP
o Uses Hundred Fists
o Very, very high Counter rate. Melee with caution.
* Monsters on this floor are immune to slashing damage.*
o Predator Claws, Spinning Dive, and Eclipse Bite do no damage.
o Fleuret-type swords (e.g. Joyeuse) do piercing damage and will work; however, physical sword weapon skills such as Vorpal Blade will do no damage. Magical weapon skills such as Spirits Within and Seraph Blade will work.
o The Warrior ability Tomahawk will allow slashing damage, however it is still quite low compared to that which you would get on monsters occupying the other floors.
* All three chests pop SW of the raised area, where the Time chest is marked on the map.
* The Items chest has 4 Ancient Beastcoins and 1-2 AF+1 items (PLD, DRK, BST, NIN, BRD, RNG, SMN, PUP, COR, DNC)
Third Floor *
Enemies: Inhumer x8 (Skeleton BLMs)
o About 9000 HP
o About 5/8 drop an Ancient Beastcoin.
o Susceptible to Lullaby and Repose.
o Linking.
*
Boss*: Grave Digger (Corse)
o About 10,000 HP
o Has all normal corse job abilities such as Danse Macabre (Charm).
* Monsters on this floor are immune to piercing damage.*
o The Warrior ability Tomahawk will allow piercing damage, however it is still quite low compared to that which you would get on monsters occupying the other floors.
* An Inhumer's highest damaging move seems to be Black Cloud, dealing around 400-600 damage to DD members without stoneskin. Recommend: Cures before Blindna.
* Occasionally one of the skeletons will be close enough to the arrival point to immediately blood aggro.
* Be careful of adds from blood Aggro, they aggro from a very long distance.
* Skeletons also have group aggro: 1 man dies and the whole party has aggro.
* To avoid mass link, start pulling at outside with Silence, Inhumer will start running right away before he will link with the other. Take care at link distance and the HP of the puller.
* The chests on this floor have about six possible points at which they can spawn. These include the southeast, northeast, and southwest corners, and a few points in the central area. Occasionally, two chests will spawn at the same point, on top of one another.
* The Items chest has 4 Ancient Beastcoins, and 0-2 AF+1 items (BRD, MNK, DRK, RNG, WAR, NIN, SMN), or crafting items (Light Steel, Darksteel Ore, Darksteel Sheet, Adaman Ore).
Also note the time box on this floor is 10 min, not 5 min as the picture says. Time chest is not under the boss.
Fourth Floor *
Enemies: Flying Spear x8 (Evil Weapon RDMs)
o About 4500 HP
o *Immune to direct magic damage (including Astral Flow, Spirits Within, and other magic damage weaponskills such as Leaden Salute).
o Always drop 2 Ancient Beastcoins.
o Linking.
*
Boss*: Evil Armory (Evil Weapon RDM)
o About 12,000 HP
o May start off with heavy stoneskin and other buffs. Dispel recommended.
o Immune to magic until all Flying Spears are defeated; then it will take magic damage as normal.
o Evil Armory's defenses are weakened as Flying Spears are defeated.
* The final chest has 5 Ancient Beastcoins, 2 AF+1 items (WHM, BLM, DRG, SAM, WAR, BLU, SCH), the Smalt Chip, and a chance to drop a Metal Chip(???%).
*Was to lazy to make this a separate topic, might get around to it later but if anyone else makes it before I do, just copy pasta this stuff in there or direct it here. Thanks @_@