Stat maxing is a process that involves leveling your characters through the Sphere Grid but specifically doing it in such a way as to ensure that your character’s stats are completely maxed out.
Completing the Sphere Grid is relatively easy but you will have to add Spheres to nodes in order to continue to increase each character’s stats. Note though that once you add a Sphere to the Sphere Grid it will appear in that same spot for all of your characters.
The maximum value for any of your stats is 255. You can view your character’s current stat values by navigating to the Sphere Grid and pressing the 
Button. The stat values that you can achieve are as follows:
| Stat | Maximum Value |
|---|---|
| HP | 9,999 |
| MP | 999 |
|
Strength Agility Defense Luck Magic Evasion Magic Defense Accuracy |
255 255 255 255 255 255 255 255 |
Maximizing the Luck stat can be extremely difficult and time consuming. It is also not necessary for completing any of the end game bosses, so it is recommended that you raise Luck as much as you can, but you do not need to maximize it to 255.
For starters, you are going to need to utilize two other strategies for leveling your characters through the Sphere Grid. These two strategies are the Quick Leveling / Power Leveling technique and obtaining Triple AP Weapons. Familiarize yourself with these two strategies before you continue:
Quick Leveling
Battling certain fiends at the Monster Arena to quickly level up your characters.
Triple AP Weapons
Obtaining weapons with the Triple AP Auto-Ability for your characters.
You now need to progress your characters through the Sphere Grid and add Spheres to the empty nodes as you progress through it. Start by focusing on one character first and check out their stats. Next, pick a stat to maximize to 255 and begin filling empty nodes in the Sphere Grid with that Sphere.
You could start with Tidus and start by maximizing his Strength stat. You will need to farm 
Strength Sphere and then you need to farm 
Power Spheres to activate the Strength Spheres that you add to the Sphere Grid. Continue filling in the grid until you reach 255 with the stat.
Some characters have higher base-level stats than others. Tidus has high Strength, so he will require less Strength Spheres to be added to the Sphere Grid than, say, Yuna or Lulu. Make sure you add extra Spheres to the grid so that all characters can maximize their stats and use a 
Clear Sphere if you need to adjust the stats.
To clarify, there are a number of different spheres that you can obtain. Purple Spheres are those used to fill in empty nodes on the Sphere Grid while Red Spheres are those that are used to activate the nodes. For example, a Strength Sphere would be added to a node and then activated by a Power Sphere.
You will need to farm both sets of Sphere types and the methods are outlined below.
Farming Purple Spheres is the more difficult of the two Spheres that you will need to obtain. You will need to defeat specific fiends at the battle Arena to obtain them. Each of the monsters that you will need to fight are outlined below:
| Sphere | Monster Arena Fiend |
|---|---|
| HP Sphere |
Ironclad (Species Conquest) |
| MP Sphere |
Vidatur (Species Conquest) |
| Strength Sphere |
Juggernaut (Species Conquest) |
| Defense Sphere |
Tanket (Species Conquest) |
| Magic Def Sphere |
One-Eye (Species Conquest) |
| Magic Sphere |
Jumbo Flan (Species Conquest) |
| Agility Sphere |
Fenrir (Species Conquest) |
| Evasion Sphere |
Pteryx (Species Conquest) |
| Accuracy Sphere |
Hornet (Species Conquest) |
| Luck Sphere |
Greater Sphere (Original) |
Farming Luck Spheres and Fortune Spheres is a tedious and drawn out process. It is helpful to farm a few of them but don’t spend too much time on obtaining high Luck as it is not required to complete any aspect of the game.
The best method of farming these Spheres, which include Power Spheres, Mana Spheres, Speed Spheres, Ability Spheres and Fortune Spheres, is to defeat Kottos in the Monster Arena. Make sure to use a Distiller during the battle to ensure that Kottos drops the Spheres that you require using any of the following Distiller items (which can be purchased from the Monster Arena owner):
Power Distiller
Mana Distiller
Speed Distiller
Ability Distiller
Kottos is and Area Conquest fiend in the Monster Arena.
Notably absent is any kind of “Fortune Distiller” which is an item that does not exist in the game. The only way to obtain a Fortune Sphere is to battle and defeat an Earth Eater. Earth Eater is a pain to defeat even when your characters are fully powered up, and every Luck Sphere node you activate will require a Fortune Sphere for each of your characters, making this a long and drawn out process if you plan to maximize Luck.
Use this method to maximize the stats of each of your characters (except Luck) up to 255. This will make many of the end game bosses easier to defeat.
