TH doesn't really effect the drop rate of anything in Davoi, each NM drops 1 of 2 items...
There is a common misunderstanding about Treasure hunter that needs to be cleared up.
It does not help you get the rarer item easier, it does help you get EVERY item easier!
It can't distinguish which item you want to drop and make it drop. lol
NM can actually pop every hour, providing that the PH orcs are killed prior to ToD, and the Nm does in fact replace one of the 5 orcs in the area when it pops, I have seen this drop 18 times in 2 years of farming Davoi.
This body piece is highly sought after and rightfully so - there aren't many decent ACC+ pieces prior to Lv.55 other than expensive rings, but due to the game's dependency on ACC when fighting XP mobs, lower levels usually demand you get it where you can.
MNK, SAM, and NIN can all benefit greatly from this piece for a number of levels, increasing their overall hit rate (and for the latter, hate control). If you've got the wallet for it, SAMs may want to upgrade to the Lusiant Haubert later.
Dropped from "Poisonhand Gnadgad" in Davoi Drop rate is exactly 11.5% on gi and 88.5% on jujitsu Sitabaki EITHER one will drop but never both at the same time DROP RATE NOT AFFECTED BY TREASURE HUNTER
Since some people are having a hard time understanding Laviot... look at it this way: Poisonhand Gnadgad has a 100% drop rate. From that 100%, there is a 90% chance you get the legs and a 10% chance you get the shirt. There is no way for Treasure hunter to raise the odds of getting the gi without having to lower the odds of the sitabaki because you can't exceed 100%. Treasure Hunter does NOT help on this (or most beastmen) NM.
I have been camping this NM for 2 days now. It usually spawns around 1 hour after ToD 0/8 so far on drop. Now for the past 6 hours I have been killing all the PH's and the NM has yet to spawn at all. So unless someone snuck in on me and one shotted the NM got the drop and insta warp on me. its 1-6+ hours IMO. I'd just buy the item if it wasn't so heavily camped at the AH
TH has 0 bearing in Rare/ex drops not every drop and like Kote of NM in castle Oz this mob drops either Sitabaki or Gi.Moon phase and day has more bearing any any drop then TH!
