User blog comment:Alb3rtusja/Can't use my Magica party - -/@comment-3215051-20161109051709/@comment-3215051-20161109090603

Chain abilities allow you to link a character to another one. In order to equip one character onto another, the one you want to equip must be level 40.

You get stat percentage boosts whenever you equip a character on another character depending on the equipped character's level, and you get a further boost if they have the same affiliation. (Vice Capital, Holy Capital, Nine Territories of Fire...)

The chain abilities only activate when the characters have the same class. (Warrior, Knight, Archer, Magician, or Cleric) The equipped character grants their ability towards the one you have them equipped on. [Kodachi]