Important : In the West section, everyone starts off with 3 BP at the start of battle. However the enemy is dumb and only Braves once per turn. What you can do is Brave the maximum amount of times per battle. For best results, you'll want a balanced team of attackers--two physical and two magical.
By the way, the 3 BP bonus doesn't carry onto chained battles--but it does for enemies, so be wary of that.
Actually, this section might even be more fun than the last! Since your party starts off with 3 BP each battle, you don't have to hold back your moves at all. So long as everyone's MP is relatively high, you can afford to Brave the maximum amount of times for an onslaught of attacks.
Don't worry too much about leaving your defences wide open as the enemies will only Brave once per turn. So as long as you defeat most of the enemies, you won't get bombarded with attacks. Then on the second turn, your characters should have 0 BP, giving you a chance to mop up.
Anyway, onto the dungeon itself. From the first entrance, follow the path in a westerly direction until you reach three tunnels going under an overpass. First, head all the way west to scoop up 1200 pg from the chest at the end.
Next, go through the left-most tunnel to climb onto the overpass. At the end is a chest with an Iceflame Shield --an amazing shield that negates fire and water damage; give this to your healer. Retrace your steps and go through the middle tunnel, which leads back to the Central section.
Cautiously follow the path to the end, remembering that every hit is a critical hit, for a chest that contains the mighty Mandarin Fist . Backtrack to before the tunnels and enter the right-most tunnel. After turning the corner, head all the west to find an Ether shimmering on the ground.
Finally, take the path leading south that you passed by. Before you can continue further, a pair of Red Helms are itching for a fight. These grizzly bears use Massacre to expend 1 BP to unleash a flurry of random hits on your party.
They have high magic defence, but are still vulnerable to earth magic. Begin by having two Wizards fire off two Soil Darts and mop up with the other party members. Since they're beasts, the Orichal Dagger from the Mythril Mines will be effective.
Once you've surpassed that last obstacle, head straight for the Adventurer and exit ahead. Despite appearances, there's no boss to be fought in the grotto, but there will be one coming up very soon. If you need more experience, you can stay and grind in your favourite section.
In the final section of the grotto, simply follow the path towards the centre. This would have been the perfect place to have an epic boss battle, but instead you'll be treated to a dramatic cutscene instead. After you regain control, head for the north-east corner and go down the steps.
When you reach the back, go south and you'll travel underneath the rock, towards a hidden chest that contains a Crimson Spear . Return up the stairs and head all the way west towards the fiery entrance. Who would've thought there was another entrance to the Temple of Fire?