This decision is represented by the mental image at the start of chapter 9.
The blue sky symbolises Zack, the white feather Angeal, and the water Aerith.
If you pull back a bit, you could say it symbolises ideals, goals, dreams.
The white feature, as well as being a symbol for Angeal, is also a symbol for ‘wings’.
After the final battle it was defeated by Cloud’s team and lost its physical body, but its mimetic legacy lived on within the Lifestream, and in “AC” it created remnants such as Kadaj.
Jenova has an instinctive drive to destroy planets, and utilising its abilities to inject a virus into its target and transform them into monsters, and to mimic other forms according to its opponent’s thoughts, it drove the Ancients to near extinction.
It was later sealed away by a counter-attack by the Ancients, and remained dormant in the ground until it was exhumed 30 years ago.
As with its use in the logo of ‘CC’, the blue sky symbolises Zack, the ideal SOLDIER 1st class envisioned in “FFVII”.
This is the image of Zack at his best and complete.