Retainers
Retainers are the people and objects that accompany your avatar on campaign, each one having a useful effect on the battlefield. Retainers are awarded for completing armour sets and by exploring the avatar conquest map and unlocking new recruitment buildings. You can choose a limited number of retainers to use in your avatar's next battle on the pre-battle screen. To assign them to your avatar, simply select retainers from the pool and drag them over to one of the vacant slots. You can also make changes outside the battle system via the retainers panel on the avatar screen, which contains a list of those retainers you have unlocked, together with ones which are still locked (and the requirements to unlock them).
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