According to the Final Fantasy VII Ultimania Omega, Cait Sith's role in the final product bears few differences to the way he was originally conceived -a robotic spy from Shinra commanded by Reeve. Since Cait Sith/Reeve grew fonder to the members of AVALANCHE, he would have developed a kinship with them and found his loyalties between them and Shinra torn.
In a reversal of his first character, Cait Sith functions as a spy for AVALANCHE and lets them listen on Shinra's meetings. He tells the party about Shinra's search for the Huge Materia and announces Shinra's fall following Diamond Weapon's attack on Midgar. Following Rufus Shinra, now president of the company, is presumed dead in Diamond Weapon's attack on the Shinra Headquarters, Scarlet and Heidegger take over and have Reeve imprisoned. Since Reeve begs for AVALANCHE's aid via Cait Sith, he accidentally blows his cover as the cat's master.
In a scenario cut from the finished product, AVALANCHE would have needed to shut down the Mako Reactors around the world to help combat Sephiroth, but would have been unable to strike all of them in time. At risk of jeopardizing his position in Shinra, Reeve would have shut the reactors down himself. The situation developed into Shinra using the Sister Ray powered by Mako Reactors, during which Reeve attempts to talk them out of working with the cannon and is arrested.
Cloud Strife, a former member of Shinra's elite private army SOLDIER, has united AVALANCHE as a mercenary for hire. Alongside AVALANCHE leader Barrett Wallace and childhood friend Tifa Lockhart, Cloud starts to dig into the layers of corruption which permeate Shinra. The team discovers many of Shinra's secrets, including human experimentation and a plot to kidnap Aerith Gainsborough, a young woman thought to be
Another Cait Sith is built by Reeve with all the memories of the preceding four versions. He uses Synaptic Net Dive after Shelke to show the World Regenesis Organization the horrors experienced by Deepground victims. Using the information, the WRO realizes Deepground is hoping to make a Lifestream pure of Jenova to summon Omega.