In the next screen, go left until Tifa arrives. She will force you to take her in your party if you don’t have her in it already. When you have made your party go left. Go south to the lower path, and then go left and pick up the Summon Neo Bahamut materia. You can jump to the Save Point, then jump north and go left. Cloud will see something and a cutscene with the Shinra will happen. When it’s over, go left again and you’ll see a ‘shield’ and some black creatures. You need to cross when the wind is almost disappeared, but if you don’t you’ll get knocked back and have to fight a Wind Wing.
When you make it across, you’ll see more black creatures. Follow them up the path and pick up the Kaiser Knuckle on the way. There’s another shield on the next screen, but this time with a green aura going past every now and again, wait until this has gone and then for the wind to subside, then cross. If you hit it, you need to fight a Wind Wing. In the next screen, you’ll see Sephiroth again, and he’ll talk for a bit. When he’s done, he’ll summon Jenova to fight you…
Jenova’s main attacks are Red Light, Silence and Tropic Wind. You might want to start off by using MBarrier and Haste. This battle can be pretty easy as the Red Light attack isn’t that bad, and physical attacks can take off quite a bit of damage, but she does have quite a bit of HP. If you feel like using Summons, use Kjata, Bahamut, Neo Bahamut and Titan. Alexander and Comet magic is also good. You’ll win a Reflect Ring, when she is defeated.
Your party will talk after the battle, and you’ll get the Black Materia back. You need to give it to someone else, who isn’t in your party. Some of your team will refuse to take it, like Yuffie, Vincent, or Cait Sith. When you’ve given it to someone, talk to Tifa. Head north and pick up MP Turbo materia on the ground. Keep goinG up and save at the Save Point. Take the Poison Ring from the chest and head north. There is another ‘shield’ screen here. This one has the wind, the green aura and a strike of lightening. Wait for them all to pass, then cross. And yes, if you hit it, you have to fight a Wind Wing. Go north.
You’ll come to a replica of Nibelhiem, and you’ll now be in a semi interactive flashback. Sephiroth will turn up followed by some guy with black hair in Cloud’s place. Talk to Tifa to continue. You’ll see Nibelhiem burning down again. When your party appears in the burning rubble, they will talk and Sephiroth will appear and talk some more. Talk to him when you can move, then talk to Tifa twice. Sephiroth wilL talk and then show you the picture taken at Nibelhiem in Cloud’s flashback. Where Cloud should be, the guy with black hair is there. Cloud goes freaky and the scene ends.
You’ll then see Rufus and the other Shinra heads talk. The scene will switch back to the other party members not in your team, and everyone but whoever has the Black Materia will disappear. Tifa will appear and make that person go into the crater. Then Tifa will turn out to be Sephiroth. The other party members will appear and the scene will switch back to the Shinra heads. Your party will then appear where the Shinra are. The person holding the Black Materia will turn up and press O a few times to get them to give the Black Materia to Cloud. Cloud will then fly up to where Sephiroth is. Hojo will talk for a bit, then watch the FMV where Cloud will give the Black Materia to Sephiroth and the crater will fall apart. Watch the very cool FMV as the WEAPON’s appear, and everyone but Cloud will escape on the Highwind.
There’ll be a flashback and you’ll come to at Junon Town.