You gain Spirit Strikes throughout the story (they are given to you as opposed to you “buying” them in the Advancement Menu – like Skill Strikes). You need Special SSP (Spirit Strikes Point) to use them. This bar will fill up slowly, so it’s best to use them in hard battles, or in boss battles.

When your characters gain enough experience (see the Main Menu main screen for the current level, experience points, and experience to reach the next level for any characters in your party), they will gain a level and receive one or more advancement points. Use these as soon as you get them to make your life a lot easier. Open the Advancement page from the Main Menu, switch to the character you want to advance, and scroll through the possible ways to spend your points. Each character increases in the various stats by different amounts for each point spent, for example, Tal will gain 500 max HP for each point, while Ailish only gains 300. Use this to your advantage, but also think of what kind of fighter you want each person to be.

This list below shows you the growth rate of each character stats.
 
 
 
You’ll notice that the character growth rate is the same as their initial stats. This simply means that if that character has a high HP, than he will always have the highest HP when all stats are maxed out, and vice versa.

A mix of strengths throughout your party is generally the best way to go, but you might prefer to, say, make Elco physically very powerful by increasing his Power, or you might prefer that he can perform lots of Skill Strikes and boost his SP. In the end, it’s up to you and how you want your characters to perform. Just remember that they all need some balance, so don’t neglect any category entirely. You might be unable to advance a particular stat beyond a certain point before you reach a certain level of experience (e.g. you can’t raise any stat more than 7 times until you reach level 20). This discourages you from spending all of your points in one area at the expense of all others. Aside from increasing Max HP, Max SP, Power, and Essence, you can also learn new Skill Strikes from the available list. To learn a Skill Strike, you must first have sufficient max SP to be able to perform it, and then you must spend an advancement point on it. Not every character absolutely needs to have every one of their Skill Strikes, but you could find some use for all of them if you tried.

Here is a table of the experience points required to reach each level.
 
 
 
You’ll notice that the character growth rate is the same as their initial stats. This simply means that if that character has a high HP, than he will always have the highest HP when all stats are maxed out, and vice versa.

A mix of strengths throughout your party is generally the best way to go, but you might prefer to, say, make Elco physically very powerful by increasing his Power, or you might prefer that he can perform lots of Skill Strikes and boost his SP. In the end, it’s up to you and how you want your characters to perform. Just remember that they all need some balance, so don’t neglect any category entirely. You might be unable to advance a particular stat beyond a certain point before you reach a certain level of experience (e.g. you can’t raise any stat more than 7 times until you reach level 20). This discourages you from spending all of your points in one area at the expense of all others. Aside from increasing Max HP, Max SP, Power, and Essence, you can also learn new Skill Strikes from the available list. To learn a Skill Strike, you must first have sufficient max SP to be able to perform it, and then you must spend an advancement point on it. Not every character absolutely needs to have every one of their Skill Strikes, but you could find some use for all of them if you tried.

Here is a table of the experience points required to reach each level.