Quick Leveling / Power Leveling
This section of the strategy guide is intended to be used when you’ve reached the end-game content for Final Fantasy X.
Many of the strongest enemies and bosses in the game will require you to level your characters through their Sphere Grids completely. This quick leveling method is for power leveling your characters and is not meant to be used if you’re having trouble defeating one of the standard bosses.
This leveling technique focuses on three auto-abilities, an Overdrive mode setting, and battling one specific fiend, the Don Tonberry, in the Monster Arena. The three auto-abilities that you will be using are:
Make sure that you also have your characters equipped with armor that has the Auto-Phoenix auto-ability so that you can revive your characters as they are KO’d.

With weapons that contain all three of these auto-abilities, you then need to set your character’s Overdrive mode to “Comrade,” which will cause their Overdrive gauge to fill when their allies take damage.
Alternatively, if you do not have Comrade Overdrive Mode, you can also use Stoic. Check out the Overdrive Modes section below for more information:
Overdrive Modes
Overdrives

An overview of the modes that you can set for your character’s overdrives.
Crafting the Weapons
You will need to obtain the weapons for starters. You can customize them yourself, but there is a more straightforward method for getting started. Check out the guide for obtaining “Triple AP” weapons below:
Triple AP Weapons

Obtaining weapons that have the “Triple AP” auto-ability, which will allow you to level your characters expediently.
The weapons you obtain through this method will have just one of the auto-abilities that you need. You will need to customize the other two abilities and add them to the weapons.
You can add Triple Overdrive by obtaining 30
Winning Formula. You can get these by defeating Ultima Busters in the Monster Arena. Alternatively, you can customize the
Double Overdrive auto-ability, though it won’t be as fast. You can customize Double Overdrive by obtaining 30
Underdog’s Secret, which can be obtained as a Monster Arena reward or by defeating a Th’uban.
Finally, you will need to add the Overdrive → AP auto-ability. You can obtain it by picking up 10
Door to Tomorrow, which can be obtained by defeating Bomb Kings in the Monster Arena.
With your weapons in hand, your armor equipped with the Auto-Phoenix auto-ability, and a healthy complement of
Phoenix Downs, you are now ready to fight Don Tonberry.

Battling Don Tonberry
Each time you attack Don Tonberry, it will counterattack with an attack called “Karma.” Karma will inflict damage based on the number of enemies that the character has killed. The formula is “the character’s kill count” multiplied by 100. If your character has defeated 1,000 enemies or more, Karma will do 99,999 damage.
You need to have a character attacking that will cause Don Tonberry to do 99,999 damage in your party. Have them attack Don Tonberry; they will be KO’d, but this will cause each of the other party members’ Overdrive gauges to fill, which will be converted into AP. After a few attacks, you can use the Flee command and exit the battle, and you will get to keep the AP.
This method will make it easy for you to gain AP quickly. In fact, at the end of each battle, each of your characters will likely have 99 Sphere Grid levels (the maximum available).

Stat Maxing
This method is part of the steps you will need to take if you wish to maximize your character’s levels and stats. Check out the stat maxing guide below for more information:
Stat Maxing

Tips for leveling your characters through the Sphere Grid and ensuring their stats are as high as possible.