If you've completed Mysterious Man/Gilgamesh rank H Mob Hunt mission, you would get Blue, Green, Red, Yellow and Black Bottle during the fishing one by one.
With the hints from the Bottles, find five letters from the locations below:
Blue Bottle
- Nabreus Deadlands, section South section from the Gate Crsytal.
Reference the picture below if you don't want to find yourself.
Green Bottle
- Salikawood, section before to Nabreus Deadlands.
Find the shack by the middle trunk.
Red Bottle
- Mosphoran Highwaste, Gate Crystal section.
Find the Wind Shrine at North-West area, check it to get the letter.
Yellow Bottle
- Cerobi Steppe,
Go turn on the windmill No.1, 2, 5, 7, 9, turn off 3, 4, 6, 8, 10. If you
do so, you will get the letter automatically, make sure double check to
confirm all of them have been fixed right.
Black Bottle
- Garamsythe Waterway, central control section where the Save Crystal by.
Go South-East abit, where you can see some mouses running round.
After you got all five letters, move on to Barheim Passage to find Gilgamesh.
Go to the longest railway in the middle known as Zeviah Span, you can see a
small area at the South of this section, and you can only reach there from
South. Enter that small area to watch a scene with Gilgamesh and Enkidou.
Here is the location:
After all, you will obtain Matamune demon rod. Now return and pass this rod to
Ruksel in Dalmasca Eastersand, continue fishing until you get Upper Reaches.
At the beginning, you can only fish on the Lower Reaches, get 5 or above
perfect fishing (no mistake) to unlock the Middle Reaches. 5 more perfect
fishing on Middle Reaches to unlock Upper Reaches.
Now with the Matamune, you can obtain Bond Of Saboten in the Upper Reaches
with perfect fishing. Continue fishing in the new fishing spot, Secret Reaches.
With more perfect fishing, you will get Saboten Crest. Now fish in the last
fishing spot, Master Den. Try your best to get 9 successfully buttons press
for the King Of Nebra, then lastly obtain the treasure for Tolo Sword,
Lu Shang's Badge.