Aside: Exploring the World of Balance

You can head for the Imperial Base right after leaving Narshe if you want to, but it may be worth your time to explore a bit. If you recruited Mog, you'll want to teach him some Dances, and there are three hidden Espers to find. Keep in mind that you'll temporarily lose access to the Blackjack after the next dungeon is complete, so you won't get another chance to freely explore for some time.

Esper Hunting

The auction house is now open in Jidoor, and among the potential prizes are two espers: Golem and ZoneSeek. Every time you enter the auction house, the item being auctioned is chosen from a list. Each item has a 50% chance to be chosen, and if it is not, the list moves to the next item. The last item available will always be chosen. Here is the list for the World of Balance:

Your choices during the auction do not affect the final price. Cherub Down is a Relic that gives the wearer a constant Float effect. Though it costs 10,000 GP at auction, you can buy this same Relic in the World of Ruin for a mere 6,300 GP. The other Relic up for sale, the rarely seen Cure Ring, costs a whopping 20,000 GP and can also be purchased in the World of Ruin (for 8,000 GP). Unless you're filthy rich, I would recommend against those purchases at this time. They will continue to appear as auction house items no matter how many times you see them, whether you buy them or not.

The two Espers are another story. If someone else buys them, they will appear again, but once you buy either, it stops appearing for sale. Golem is more likely to be put up for auction and will cost you 20,000 GP. There's no other way to obtain this Esper, though it will still be available for auction in the World of Ruin. Golem is the only source of the Stop Spell in the World of Balance, and its unique Earth Wall summon and +2 Stamina on level up can both prove highly useful. ZoneSeek is seen more rarely but is oddly cheaper at 10,000 GP. This Esper offers no new Spells but does teach the invaluable Osmose at a ×15 learning rate. Even better, ZoneSeek offers Mag.Pwr +2 on level up. It is well worth the money and time investment needed to purchase it.

The third hidden Esper is much easier to obtain. A man in Albrook mentions that someone was trying to sell a glowing stone, and left for Tzen when he found no takers. If you return to Tzen, you may notice that man wandering the northeastern woods. Speak to him and he will offer a piece of magicite for 3,000 GP. This is Sraphim, a healing Esper that can teach various useful spells at very high rates. If you wait until the World of Ruin to buy the magicite, the price drops to 10 GP, but Sraphim is worth every penny now.

Note that while the occupied towns of the southern continent are open to you, Vector is not. The Guardian is waiting right at the entrance, and is just as invincible as it was outside the Imperial Palace.

Grenades

Completionists will be interested to learn that there is a rare World Map encounter you have to go out of your way to find. This is the Grenade, and it has its own Rage, though not one of particular note. They can only be found on the heavily forested Island West of the Veldt, and even then only 1 in 16 encounters will be with a Grenade. Otherwise, you will be fighting Bombs, either solo or in groups of six. Why is this Monster so hard to find? Who knows. Just keep in mind that Grenades may counter a basic Fight Command with Exploder, which can really hurt.

The Veldt

Finally, for the first time since you initially recruited Gau, the Veldt is easily accessible. While you previously had to trek all the way back to the Returners' Hideout and follow an interminable sequence just to teach the poor guy one new ability, now you can train him up whenever you like. (For a while, at least.) If you want to make effective use of Gau, Veldt training is important. It's also a good place to teach Characters Magic, since they will gain Magic Points but no Exp from battles there.