Once you've collected all the treasures on Gurgu Volcano B2, take a breather to prepare for your assault on KARY. While Gurgu Volcano only has five floors, you'll pass through the Third and Fourth twice each. Keep in mind that KARY has no elemental weakness, so you don't need to conserve those spells during your trip to confront her. (That said, you may want to make sure you have a few castings of SLOW, MUTE, and/or HOLD, and at least one AFIR.)
Gurgu Volcano B3
B3 is a disappointingly simple floor after the treasure fest on B2. You won't find any treasure on this part of the floor, nor the second part you will visit a bit later. What you will find are waves of lava and a simple east-west path. The stairs to B4 are to the east. There is only a dead end to the west.
The R.GOYLES are mercifully absent from this and the deeper floors of Gurgu Volcano. R.HYDRAS are now more common, and you'll begin running into CEREBUSES. Nothing about them is any more threatening than other monsters you've fought, but they frequently gain surprise on the party. They also feature a SCORCH attack that deals minor Fire damage to the entire party. For some reason, you can't run from combinations of WzOGRES and CEREBUSES.
Gurgu Volcano B4
Like B3, B4 is divided into two areas. The first area is just as uninteresting as B3, with a floor covered almost entirely in lava. The stairs to the second half of B3 are located in the southeast corner, so make your way through the floor with that in mind. There are dangerous encounters here, so it might be wise to walk in the lava as much as possible.
Back on B3, you'll find a number of interconnected rooms and a whole lot of lava. The quickest path to the stairs to the second part of B4 is south, west, and south again. The southeast path is a dead end, and the two upper western paths loop around and connect to one another.
You will finally find treasure on your second visit to B4. However, be careful, because there are a variety of new, dangerous enemies here. Grey Ws deal a lot of damage, but don't have any special attacks. R.GIANTS are similar, with even more offensive power at the cost of some Absorb. With 300 HP, they aren't easy to take down quickly no matter what you do, and they can appear in pairs. You'll rarely run into an AGAMA, who also double as treasure guardians in several locations on this floor. They have a lot of HP and their HEAT attack deals enough damage to be considered a minor threat.
The scariest monster on this floor, and possibly the entire game to this point, are the super-rare Red Ds. Defensively, they're basically on par with the other creatures you'll find here, albeit with somewhat better Evade. The bad news is, they have a tremendously powerful attack, on par with R.GIANTS. The worse news is they also have a BLAZE attack which is even more powerful than FIR3. Put up AFIR as soon as a Red D appears, even if you intend to run. If you have level 6 spells available, this is an excellent use of STUN. The only good news is that they drop 4,000 G upon defeat.
This floor is arranged as a series of branches leading to six treasure rooms. You'll start next to one such room in the northeast part of the floor. You'll find 2,750 G and a SOFT Potion here. Both treasures are guarded—the left chest by an AGAMA to the south, and the right chest by a Grey W to the west. Both can be avoided easily by approaching from any other direction.
If you follow the path west, you come across a second treasure room at an intersection. The only treasure box here contains 1,760 G and is not guarded. You'll find a fantastic treasure room to the west, though this is a dead end. In this room you'll discover 8,220 G, a PURE Potion, the Flame Shield, and the Ice Sword. The Flame Shield is in the northeast chest, which is guarded by a Grey W. It is a nice upgrade, but it resists Cold, which isn't much help right now. The real prize is the Ice Sword (which, it should be noted, can also be found in another room on this floor). Even though its elemental nature doesn't work in this version of the game, the Ice Sword is a huge upgrade over anything else you've seen, both in terms of Attack and Hit Rate.
After collecting the treasures in the northwest room, return to the intersection and turn south. You'll reach another intersection with a fourth treasure room. This one contains only 165 G split between two chests. To add injury to insult, there is an encounter with a Grey W two squares south of the top chest. Make sure to step around this central square while collecting the Gold. The eastern path leads to the fifth treasure room, which is the other room you can find the Ice Sword in. You'll also find a HOUSE and 2,000 G here.
Finally, return to the fourth room and head south to find the final room and the stairs to B5. This room contains 1,250 G and a Wooden Staff. There are AGAMAS just west of both chests. You can collect the 1,250 G in the south chest safely by approaching from the south, but you'll have to fight if you want the worthless Wooden Staff. (And don't think this is the most useless guarded treasure in the game. No, not even close.)
With the Ice Sword in hand, it's time to move on to the final floor and confront KARY.
Gurgu Volcano B5
The bottom floor is a sprawling mass with eight rooms branching from the central stair area. The north, south, and northwest rooms are empty. Oddly, all three eastern rooms contain the exact same thing: one unguarded chest containing the same SOFT Potion. Not only is this a shared treasure, but you can (and probably did) find the same SOFT Potion back on B4.
That leaves two directions: west and southwest. You'll most likely want to head west first, because you will find the Flame Armor in that direction. You will have to fight three guardians to claim it, however: an AGAMA on the approach, a Red D in front of the chest, and the AGAMA again on the way out. The Flame Armor is well worth the effort, providing as much Absorb as the Steel Armor with 23% less Evade Penalty. The resistance to Cold is just a nice perk compared to that.
When you're ready, head southwest. There is a lava-filled path between the rooms and the center, which will cut down both on trip time and the number of encounters you need to fight. KARY's room is similar to LICH's. Inspect the ball to begin the fight for the light of the ORB of Fire!
KARY
D&D veterans will recognize KARY as a Marilith, which explains why she is resistant to Cold rather than weak to it as you might expect of a Fiend of Fire. It doesn't explain why she's the only monster in the game with a weakness to Status, however. SLOW, MUTE, and HOLD are all incredibly potent if they connect, and each has approximately a 35% of success. However, if these spells fail, you can be left somewhat defenseless.
A more conservative strategy is to use spells like AFIR and FOG2 or INV2 early in the fight to blunt KARY's attack. She has six powerful attacks, and she will use them almost 2/3 of the time on average.
Because KARY resists all three basic elements, attack magic is useless in this battle. Your main offense will come, as always, via melee attacks augmented with FAST. This is one fight where you may actually want to use LAMP if you have it and if KARY hits your front-line Warriors with DARK. With 50 Absorb, every bit of offense helps. Of course, if you manage to hit her with both SLOW and MUTE, she will be almost completely unable to hurt the party and you can use whatever strategy you like.
Once KARY is defeated, you can teleport out of Gurgu Volcano just like when you defeated LICH. Congratulations, you've now restored light to half of the ORBS!