...AAAANNND NOW!!! GETTING T3H MOST POWERFUL WEAPON IN T3H GAME!!!! The Zodiac spear!
Time frame: after Raithwall's Tomb/Patient in the Desert Sidequest.
First-off, we have to get that sickly patient cured in the Dalmascan Estersand at the villiage by t3h river. You must have completed the flowering cactoid hunt in the Estersand, as well have KEPT the Great serpentskin you got when you defeated the Marilith hunt. O_o You DID keep it...right? If you haven't done either of these hunts (as well as others) do them now. Dantro's wife will ask you to bring her some readily availible (at this point) ingredients to help the wittle moogle feel all better o_O So bring them ALLLLL to her. Got it? Good. *hears someone say they don't get it* -_-' Ok, I'll tell ya briefly what you'll have to do. 1) She'll ask for some kind of 1337 seashells that are along the beach - there are....like, 6 (or so.) There are some IN the village and there are some OUTSIDE of the village - make sure you get them ALL. They are by the beaches both in and outside and shine when she asks for them. Next she will ask for some kind of special medication - there are two vials of this stuff near where Dantro is sitting on his box. Get BOTH of them...lastly, she will ask for some Dewdrop pebbles or somethin...they are across the river - North of where you are at by 3 screens. Again, make sure you get them all (I belive there are like 4 or so) and they are by the pink, flowering trees by the canyon/hill you have to climb up. Lastly, she will ask for the Great Serpentskin to make a broth to bring his fever down. Hopefully you have it. After you give this to her your task is complete and he will soon recover - just go outside the village for a few minutes, re-enter, and you will find him around the back of her hut. This moogle will give you the Barheim key, along with a GOLDEN AMULET (LP earned x2) if you did everything correctly. If you sold the Great Serpentskin - it will take some time before he will recover - but you can still get the key. Actually this only unlocked for us the ability to travel North of here towards where you got the Dewdrop pebbles. We need to head north to get to the Mosphoran Highwaste, and eventually - the Salikawood.
Upon arriving in the Highwaste - make sure you purchase up to 5 more Golden amulets as well as 3 sets of Theif cuffs...these items will be a valuable asset to your entire party (and quest in general when you are trying to get loot/monies for later.) For now - move onwards to the Salikawood.
The Bombking: The Salikawood has a gate crystal you can (and should use.) Frankly, this is a great area (if you have the patience for it that is) to make money by stealing over and over from the Bombking one screen north of here. Simply steal, leave, re-enter where he is - rinse and repeat until you have as much loot as you want. Once you are ready to move on, prepare for the fight against him...it may be long depending on how well you've followed my guide, leveled-up, and how good your equipment is. I suggest having a party with one character equiped with the Nipholaoa accessory - you can purchase one of these from the merchant who supplies the hunters in Rabanastre after completing most of the hunts up to this point in the game. With it - you will EASILY be able to fell the Bombking and his kids - I'll tell you why: the Nipholaoa accessory reverses recovery items. O.O Do you know what that means??? If you throw a remedy at an enemy with one of these babies equiped it puts every status in the game (except the ones they are immune to) on the enemy! 0.0 See what I mean?!?! The Bombking will be slowed, poisoned, asleep, diseased, etc... essentially making this battle toooooooo easy. If you choose not to follow this path - just be aware that as he gets low on health he will cast renew - AND revive the bomb kids
Your choice. After defeating him - return to the save crystal. This is/can be the tricky part.
Next - swap out all your characters so they a) have Shell, Protect and Libra cast on them, b) have as many HP + augments as possible, c) have the licenses for the best equipment you have available to your main squad. Alternative, if your levels/equipment are high enough - you may choose to fight your way through the Nechrol of Nabudis - but at this point I don't recommend that. Simply surviving is difficult ENUF! Here goes.... ;arf Run north of where the Bombking was, and eventually head West to get to the Nechrol - you should only have 1 active party member for this to work. HOLD DOWN R2 TO FLEE ALL BATTLES here! The Bachelmy that inhabit this place are awful to try to survive-through their attacks and magicks - that's one reason we are running - the other is that it is a LONG way to the effing spear! WHEN your character(s) die - remember to swap their equipment onto the next character so they can take several hits before getting KOed.
Head East - past all the traps. Around the large, central area, then South to find a staircase to the next area. Next - stop and revive and recast your buffs. Then head East again and North, then Northeast (you'll see what I mean when you are running) to find the next (and last) area you'll have to run through...remember to revive and rebuff any fallen party members. Now head a little North and as soon as you can go East do so. Follow and hug the wall to your north around the next bend and you'll eventually come to a room with 16 chests...now - if you DID NOT touch certain chests in the beginning of the game there will be 16 here - otherwise there will only be 15 - and you will have lost the Zodiac spear - although you have < a 1% chance of getting another one later in the Henne mines...this is the only foolproof way to get it (and you'll want it) this early in the game and with consistency.
After obtaining it - high tail it outta there and work you way back to the save crystal - congratulations. Have a sigh of relief, a smoke, a colonoscopy...whatever floats your boat. >_> You now have an attack valued at 150 - which at this stage in the game should be doing between 1900-over 3000 damage depending on what level you are at.