[DEV1006, DEV1018] How to improve retainers?

[Mr_Gyactus]

Let them actually level up somehow, like they're all supposed to since they all say "level 1" but nothing every happens.

I agree. Retainers can be used for some gambling minigame, for example races or card games, or they can level up selling things. levelling they can gain skills, improve the storage, acquire cosmetics.