This is pretty much your last chance to do any of the EXTRAS or others not mentioned in the body of this walkthrough. Of course you can always exit the Crater in which you are about to enter, but it is a pain in the neck. So, pilot the Highwind to the Northern crater, and land in it. Climb down the ladder, and slide down the cliff.
In this screen, you will see a downward spiral into the ground, and a cave. This cave is to be used if you want to exit the crater. Now, almost all the chests contain ---- Sources, (Mind, Luck, e.g.) Except for a few. One of the chests contains a Save Crystal. This is to be used near the end, for there are no Saves in this area.
Keep going round and down till you reach the next screen. Here, go left, then go up the ramp and left for a chest. Then head back right for an HP Absorb Materia. Go back down the ramp. Now go right, and then down for some chests. After getting the chests, go up, and on the left side, if you go up and right there is a chest. Go back down to the next screen.
This time, go left into the cave. In here, if you go through the right hole, there is a chest. Now go down from there to get another chest, and then exit through the lower exit. From here, go right for a chest. Backtrack through the cave and reach the entrance. Now go right, down then left for a chest. Jump upward. Now go left and down into another cave. Get the chest here, then exit.
Go across, and then fall downward. Go right and fall downward again. You'll go through another cave, when you exit it, fall downward and go to the next screen. Next screen, go down the 2 stalactites to reach your pals.
They'll want to split up. Note: The main purpose is for the others to grab chests in these passageways. Chances are they wont get them all. When you finally reach the Meeting Point, you can make your way back through the Left, Lower path to the screen with 2 stalactites and go through the other passages as well, getting all the chests. This is important because in the Right: path there is a Mystile!
THE RIGHT PATH
Here, go down the spiral. Note here: When you climb down this stalactite, you can't go back up. Head on down, grabbing the chest and the item bag. Get the chest in front, then go down from there to get another chest.
Go back up, then right and up to a fork. The left path has a chest. The upper path leads on to the next screen. Here, simply cut across the skeleton and go down. You'll see another spiral. Go down, and you'll reach the Meeting Point.
THE LEFT, UPPER PATH
This is a slimy area. Here, there are rare enemies called Movers and Magic Pots. Movers come in threes, give 2400 AP, and 17000 gil. Magic Pots come in ones or twos, give 1000 AP, 10000 EXP, and ? Gil (I forgot) but you have to give them an Elixir before you fight them and kill them. Use W-Item trick to overcome this obstacle. (Just like in FF5, the Magic Pots in Phoenix Tower.)
Go right for a chest. Now go up. To cross, go left, to the water, then press up and you'll go underwater and appear on the other side. Go left for a chest. Then go straight to the next screen.
Here, this is another slimy area. Go left, then left again for a chest. From here, go left, then press up. You'll go underwater and appear on a rock. Grab the Shield Materia. Climb down. Get the chest. In the SE corner of this screen is another chest. Get it. In the next screen, there is no slime (and no Movers/Magic Pots). The purple dot is a W-Magic materia. Go thru the exit and you've reached the Meeting Point.
THE LEFT, LOWER PATH
Hop down the stone columns and get the chest to your left. Head right and hop up the stone columns to arrive at a chest. Go back to the first treasure chest and press against the bottom of the ledge. You'll hop down to a column where there is a chest. Go to the next screen.
Here, hop down the stone columns and then go left to find a chest. Then go east and north. There's another chest here. Go west, then follow the path south and hop across the columns. When you reach the bottom of the screen, run to the south.
In this area, go to the right and press down to hop down to a small ledge. Below is a larger ledge and a green chest. Walk to the left across the thin stone bridge, drop down a level, then keep going right until you see some stone 'steps'. Go down them; to the left is a green chest. If you walk to the left, you'll jump down to a low ledge. Nearby, there is a ball floating in the air. Hold Up in order to jump from a small ledge to a larger ledge, and when you get near the ball, tap O repeatedly. If you timed it right, you'll be able to take the ball, which is actually the Mega All materia.
If you missed it, just press left to jump back down to the lower ledge and then try again. You can only get the materia while jumping to the small ledge, not while jumping from the large western ledge.
Now go to the other end of the large ledge There's a chest here. Now go south and go down to a lower area. Keep walking south and you'll reach the Meeting Point.
Use the Save Crystal here. Now enter the screen and get the items your pals picked up for you. Equip your materia, then head down.
You must hop from ledge to ledge. There are Iron Men with 20000 HP here. Let them attack you until your Limit bar is flashing (ONLY IF YOU HAVE L4 LIMITS). Then run, not using the limits.
Down here, you fight Jenova: Synthesis, then if you kill it quickly enough, then you'll have time to re-equip and form 2 groups. This 2 groups crap isn't necessary, just form one and use it. Then you'll fight Bizarro Sephiroth, and finally Safer Sephiroth and Sephiroth himself.
BOSS: Jenova: Synthesis & Arms
LV: ?? (Jenova Body), 61 (Both Arms)
HP: 60000 (Jenova Body), 10000 (Left Arm), 8000 (Right Arm)
MP: ??? (Jenova Body), 600 (Both Arms)
WEAKNESS: None (All)
STRENGTH: None (All)
If you have L4 limits and built them up, use it with your Ultimate Weapon equipped. End of battle. Or summon Knights of Round. End of battle. Or, batter away with Summons, Coin, Magic, Throw. If you do not defeat her quickly enough, she will cast Ultima (a countdown will appear) and you'll get no EXP or AP.
BOSS: Bizarro Sephiroth A-E
LV: 61 (All)
HP: 40000 (A), 2000 (B), 1000 (C), 4000 (D-E)
MP: ??? (A), 400 (B-E)
WEAKNESS: None (All)
STRENGTH: None (All)
Cast Knights of the Round. End of Battle. Otherwise, do as follows. Cast Wall, Haste, and Regen on all. Cast Resist on All. Make sure you have Full-cure and Cure3. Coin toss, Throw and pummel away at each body part. Each time a part dies you are asked whether you wish to switch teams.
Doesn't matter. All you have to do is kill all the other parts and the core (part C) will die as well. This is backed up by Knights of Round, if you use it, the core receives no damage, but Bizarro Sephiroth dies anyway. You want to use stuff that affects all the parts, like Ultima, Coin, Bahamut ZERO, etc. Therefore, part A will do nothing but Bizarro energy and reviving other parts. Then When you Bahamut ZERO kills part A along with other parts, the core dies and you are now ready to fight the last battle.
BOSS: Safer Sephiroth
HP: (Cloud's level) x (approx. 1200)
Safer Sephiroth's stats are based on Cloud's stats. The better Cloud is, the better Sephiroth is. You can cast Knights of Round twice, and be done with it. Or cast Haste, Wall, Regen, and Resist on everybody. Resist guards against the effects of Supernova, an awesome move (well, not for you). His attacks do about 3500-5500 HP damage. Be sure to have HP Plus materias.
Now batter him with Coin and Mime, or summon Bahamut ZERO, mime that, cast Ultima, Flare, anything! You gotta go all out, this is the last battle. He is pretty easy for a last boss, I mean he has less HP than Zeromus of FF2/4j and your most powerful attack in that game was 9999! Here you have KoR, + Miming for free!
When this ends, the party will escape, and Cloud will fight Sephiroth one-on-one. It's not too hard, come on! Then watch the ending. No need to pat yourself on the back because this wasn't hard at all, but if you defeated Ruby, Emerald, weapons and got everything possible in the game then I give you permission to do so.