The following is information on Final Fantasy Tactics. This features Cloud as an optional character, about mid-way through the game. Aerith is also featured, but only for a small period of time.
It begins at Zarghidas Trade City, a Flower Girl asks Ramza for a flower (for one gil, who knew?) You can get one if you want, but if you want Cloud, then buy it. After a long process, Cloud comes into this world. But what's weird is that his sign here is the Aquaruis. Cloud remembers who he is, and says he's from SOLDIER. Then has a breakdown and mumbles "stop...stop it...phiros." This is obviously Sephiroth. Well, anyway, after a while, you can go back to Zarghidas Trade City. Here Cloud sees the familiar Flower Girl, and doesn't say much, then leaves. A monk, 2 squires, and 3 theives show up. The monk demands his 30,000 Gil. Here, this is where he says her name, Aerith. He doesn't accept the one week offer, so suggests she should sell her body instead. Cloud shows up and pushes the monk to the ground and the Flower Girl leaves. They end up fighting in a battle, in which Cloud doesn't really do anything.... he just keeps moving away. After the battle, Cloud says he lost something very important, and must go to the Promised Land.

Getting Cloud in FFT takes a lot of time and a lot of patience. It got extremely frustrating at times. My advice is to use a gameshark for more strength. And if you really love Cloud and Aerith, you'll do it. Now, to get Cloud, Mustadio MUST be alive, if you didn't murder him and turn him into crystal, then follow each step below. If you did, you can kiss Cloud goodbye.
- The first time you go to Zarghidas Trade City, buy the flower from the "Flower Girl."
- Head to the Goug Machine Factory. There will be a scene between Ramza, Mustadio, and his father, Besrodio.
- Go to Goland Coal City, and read the Ghost of Colliery rumour.
- Go to Lesalia Capital City, and after a while, Beowulf will ask to join, say YES.
- Go back to Goland Coal City, and beat four battles. The last battle, you must save Beowulf's friend/pet, Reis. She's a lot of help.
- After the battle, you must except Beowulf and Reis.
- Return to Goug, and you'll get Worker 8....after a hilarious scene (poor Mustadio!!)
- Go to Zeltennia Castle, and read the Cursed Island rumor.
- Go to the temple north of the castle, and defeat Worker 8.
- Go somewhere else, and a scene will happen with Reis. Accept her. (Isn't this a tad bit futile?)
- Continue normally as directed in the game. Basically go to Limberry Castle, then to Igros Castle, and defeat Ramza's eldest brother, Dycedarg, and Adramelk. After that, return to Zarghidas Trade City, and rescue Cloud.
And there you go!