The easiest way to beat Jenova and the chariot guy is to make sure all your guys are less than 3 levels away from level 100.
Make sure all your items are mastered and all your sumons are on your characters.
Keep striking em with the summons, and make sure u have plenty of Potons, Revives , Pheonixes downs and lots of Ethers, you'll need em.
Then when you get to Sephiroth it will be a 1 on 1 between cloud and him. For this i would make sure hes at atleast level 98, and use knights of the round on him.
He will die straiht away, it's the easiest battle in the game. Well i thought it was anyway.
We have more cheats and tips for this game here, Final Fantasy VII cheats
Comments for this hint