Зом100 згадався) 

リンダさんは女王様なのか 

このゲームで、一番思いやりあり、穏やかで優しい美人キャラ。好きになりました。 

 

 

 

Does it just improve it by increasing its damage, or does it improve it in some other way and increase its damage? 

It normally only recovers then, but there are exceptions, such as the 'SP KO' ability seen here.