hey sega chief
the final battle with the first sephiroth is broken
he keeps on recorvoring full health
That's intended; his Torso part is healed for Recovery in order to make it much harder to rush through the fight without taking out the limbs first. To beat Bizarro, you have to use all three teams:
1) You'll start with Team 1; have them destroy Bizarro's Left or Right Arm. An option to swap parties will appear: Select 'Yeah, a little' to swap to another team.
2) You'll now have control over either Team 2 or Team 3; have them destroy Bizarro's Head, then the Arms, and finally the Core (don't swap parties when prompted until this is done, select 'Not really' whenever it appears). When the Core is dead, you need to swap over to the final team. If the prompt doesn't appear after killing the Core, then wait until the Head revives and kill that to get the prompt to reappear.
3) With the final team, do the same as before; kill the Head, the Arms, and finally the Core. When that's done, swap parties again until you get control over Team 1 (the one with Cloud in it).
4) This team can ignore the Head; kill the Arms, and then the Core. When this part of the Core dies, the boss will be unable to heal it's Torso. At that point, attack the Torso until it's destroyed. The fight will then progress onto Safer.