Expression

Expression is the feelings and emotions of a Villagerian/characteroid.

Villagerians
Villagerians always have feelings and emotions, although the amount of feelings and emotions varies for each Villagerian. The only exception would be Systely.

Characteroids
Characteroids have feelings the same way as Villagerians do, and the amount also varies for each characteroid.

Summonoids
Summonoids also have feelings, but many of them have an option to turn their feelings off and back on any time. Summonoids without an expression switch always have feelings. The amount of feelings also varies for each summonoid, whether they have an expression switch or not.