Alright, so after discussing with Li I've decided that I will come up with a way to rank up abilities and make it fair. This is a new system called the ARU System which allows you to gain points to upgrade abilities based on what type of abilities they are. Here you will learn the ARU cost for each type of Ability as well as several ways to gain ARU Points.
First we will discuss ARU in a total. ARU Points literally translate into Ability Rank Up Points. These points can be gathered together, and once you have enough, spent on upgrading abilities. Upgraded abilities are stronger then original abilities. This being said of course there is a limitation on how much you can level up your abilities. We will get to that in a moment but first I will now List what type of abilities cost what.
Normal: 2 ARU Points
AOE: 4 ARU Points
Multi-Target: 3 ARU Points
Genocide: 5 ARU points
Chain: 4 ARU Points
Burst: 3 ARU Points
Combo: 5 ARU Points
Quick: 2 ARU Points
Charge: 3 ARU Points
Incantation: 4 ARU Points
Magic Circle: 5 ARU Points
That being said, I might make it known that if your abilities have multiple tags that means they'll be stronger then normal, which means the ARU point cost must be combined to allow level up. Now moving on from this I would like to talk about Ability Rank Limitations, Each type of ability has a Limitation for its level. This is to stop already powerful abilities from getting far to much more powerful.
Normal: Level 6
AOE: Level 4
Multi-Target: Level 5
Genocide: Level 3
Chain: Level 5
Burst: Level 4
Combo: Level 3
Quick: Level 6
Charge: Level 5
Incantation: Level 4
Magic Circle: Level 3
As a note all multi-tagged abilities can not be raised past level 2, This is to ensure as said before that all abilities don't become to overpowered. That being said, We'll cover lastly the several ways to earn ARU. There are several ways to earn ARU and by doing so you'll be able to level up abilities to how you desire them to be. These can be from Showing Excellence in Battle, Every 3 Levels you gain, Showing smartness during a mission, exhibiting the ability to detain a situation and defuse it, thinking of things others didn't, or even simply being there or completing secret objectives. These are only a few ways to do it, just remember all your actions can reflect and allow you to gain secret things should you do something amazing.