The only side quest within this game and accomplishing it is a quite feat itself. The story behind this side quest is quite good as well. Here is the complete steps how I obtained Cloud within this game.

1. Chapter 4. Go to the Machinery City at SW of the map. You'll encounter a brief scene with a mysterious device that reacts to your Zodiac stone. Since it's not the correct Zodiac stone to begin with, you must find the right stone.

2. Go to the city right below the Capital city. Go to the pub, choose the rumor option, and choose to hear the very last one.

3. Go to the Capital city where you'll encounter a holy knight who asks you to join to find the holy dragon.

4. Go back to the city right below the Capital city. You'll fight a series of battles until you come to save the holy dragon. The holy dragon was apparently a friend of your new holy knight. You MUST accept this dragon as your companinon.

5. Head back to the Machinery City and the mysterious device will become a robot. You can choose to have this robot as your new companion.

6. Progress more into the main story by opening the dam. New cities will be revealed. Go to the Northern city where there is an island at the north. Enter the pub and choose the last entry in the rumor section. It will reveal a path to the island, but nothing will happen at there if you choose to visit.

7. Go to the next city. You'll encounter Aerith selling flowers. You MUST buy the flowers from her.

8. Go back to the Machinery city. Another device is found and reacts to your Zodiac stone once again.

9. Go to the island, and fight the Robot #8. It'll be resurrected once after it's defeated.

10. The holy dragon turns to a woman and reunites with the holy knight. You can choose to accept this woman, Dragoner, as your companion if you wish.

11. Head back to the Machinery city and it'll bring back Cloud from the other dimension. However, he'll run off shortely after having a headche.

12. Progress more into the main story and defeat your oldest brother who turns into another Zodiac stone monster at Yigross castle, located at the west of the map.

13. Upon your return back, you'll encounter Aerith once again at the same city. However, she's being pressed to repay money by a group of thugs. Cloud comes to save her, but the headach prevents him from fighting effectively. If you defeat the thugs with Cloud, he'll now join you.

14. Cloud level starts from 1 with some equipments. Notice you cannot equip heavy armors or helmets. You can equip swords, but only Materia blade will allow him to use the Limit attacks. The Materia blade can be found at the top of volcano area with Item Search ability. You can find this any time within Chapter 4.

15. Don't expect FF7 flash style animations. It's totally disappointing to see Cloud performing the Limit attacks with single animation...