How to defeat Beatrix in Cleyra in Final Final 9

While Beatrix's hp is 4700 you only need to let her lose a fraction of that HP for the fight to end as she will stop the fight and leave after losing some of her HP.

Beating this battle is easier if you have Quina in your party, however it can still be beaten without her. In case you have Quina use her for healing every turn. 

Freya's lancer ability causes a lot of damage and also steals MP from enemies. Keep using it until you run out of MP then start jumping.

One of the powerful attacks for Beatrix is the thunder slash. The damage of this attack can be greatly reduced if you used an item that can absorb thunder attacks such as the coral ring.

If you have Quina in your party then let her use her mighty guard to protect the party from Beatrix's attacks and to reduce their effectiveness.

Beatrix's attack shock wave deals around 800 damage to a single character. At this point it would be hard to have a bigger HP and so this attack will usually kill a player instantly.

To reduce the power of the attacks let all your party stand in the rear row. If you have Equipment that protects against thunder then you can move Zidane and Freya to the front line since they will be the one attacking Beatrix. (See How To Win Final Fantasy 9 Card Game)

Using Freya's Reis' wind ability can help a lot since it will allow you to Regen your HP.

When Beatrix cures herself know that the battle is about to end. Stop curing and let all party members become offensive.

Many players believe that this battle has a time limit and that your goal should just be surviving until that invisible timer runs out.

When Beatrix casts stock break, which reduces the HP to 1, then know that the battle is over. (See How to defeat Scarlet Hair in Final Fantasy 9?)