So just how good is this Spear of the zodiac thing and how do I go about getting it? I heard you can screw up the process of getting it really early on if you don't know what youre doing.
150 attack(highest in the game), don't open 4 chests in the game:
1) chest right across Old Dalan's house
2) anything in the Rabanastre Palace(the kitchen where you pass the guards)
3) Nalbina Dungeons, the room where you get your equipment back
4) the 16 chests on the Phon Coast
If none of these are opened, you get it at the Necrohol of Nabudis in the room with lots of chests, closest row to the entrance to the room, second from the left. DON'T equip Diamond Armlet.
You can also get it extremely rarely at Henne Mines in the hidden area(Mindflayer beaten, 10 Espers controlled), or abuse the RNG like this:
http://www.youtube.com/watch?v=6ttyn6AZxqYeither way, if you have missed it, don't worry, the game is perfectly doable without it.
There are always Tournesol, Masamune+Genji Gloves(missable), Ultima Blade, Excalibur(for Hell Wyrm) and Yagyu Darkblade(for Yiazmat)