First you have to find the npc Jared, who travels across several locations, such as Incheon, Carlin temple and Thais temple.
After finding him, you will have to say Hi - Mission - Yes
He will explain to you, a giant sea octopus attacked him on his last fishing trip, and that he seeks revenge now.
Travel to Oken and head out of the eastern entrance here:
then proceed by going to the north until you find yourself here:
Fish to the west until you eventually catch a Mean Octopus and kill it.
Proceed by going back to Jared reporting about your kill by saying
Hi - Mission - yes
He will ask you for another favour, which is going to Allen and asking him to make Jared new coutrains.
You can do that by going to Venore, going south east of the boat to Allen and saying
Hi - Mission to him.
He will explain to you, that he needs a magic wool in order to proceed the request.
Now you will have to find the magic wool for Allen.
Head out of the venore south entrance
follow the way to the south west
head up the stairs, follow the way and go down on the other side again
now follow the way to the south west and then head to the north here:
until you reach here.
Use a shovel to open the loose stone pile and go down.
Go to the south east and then eventually head to the south here:
open the door and then the chest in order to obtain the magic wool
After that, report back to Allen and talk to him saying
Hi - mission - yes
He will tell you that he needs some time in order to finish the courtains. (24 hours)
After 24 hours, talk to the npc again, saying Hi - Mission
By doing that, he will hand you out Jared's courtains.
Now go back to Jared, and talk to him saying Hi - Mission - Mission
He will ask you for another favour. Now you will have to head to Gengia, and find the npc Feizuhl.
Hes located up the ladder north west from the depot.
Talk to Feizuhl saying Hi - Mission - yes . The npc will ask you for a favour aswell, which requires you to go to senja.
In order to get to senja, walk north west from carlin, until you eventuall find the npc Nielson and ask him for a passage to Senja.
In senja, head to the north east until you eventually reach this castle here:
enter it and head up the stairs to the west and grab the crystal from the chest here:
After that, go back to gengia and report back to Feizuhl by saying Hi - Mission in order to receive Jareds back of goods.
Now report back to Jared, prepare yourself with supplies/your team and talk to Jared by saying Hi - Mission Note:By doing that, you will get teleported to hell Thais, having two Orshabaals, two Bazirs and an Infernatil greeting you.
Fight your way to the south east, while having to fight alot of Bazirs, Apocalypse, Orshabaal and Infernatil to the house here and use the dead tree on the left to get your reward.
After that, in order to get back, head to the north east and you will find a teleporter back to thais.