An Imp's mask is a representation of what feeling the imp was created from. Though each mask is unique Masks are classified in 4 different classes.
Flat mask (top left)
These are one of the two most common mask types. This being worn by Imps formed from emotions that fall around the category of sadness. These Imps sulk all day and always bring a doubtful air about them, they like to make people think of the absolute worst outcome. it isn't quite hard to find these types But unless you feeling sorry for yourself best to leave them be.
Beaked mask (Bottom Left)
This is the second of the common duo of Imp masks. This is worn by imps Formed from angry emotions. The Imps that wear these like to attack and warp ones sense of thinking, best you stay away or someone might get hurt.
Beast mask (Top right)
This is one of the two uncommon masks classes Imps that wear these tend to live alone. Specifically speaking Imps wearing beasts masks are formed from emotions similar to that of an animal and are dangerous to be around. Their actions are unpredictable so be careful of you ever confront one!
Shattered mask (bottom right)
Any Imp of any mask class can become this way through a series of very unfortunate events, but Imps whom wear this voluntarily are much of a mystery. Eventually the masks chip away till its completely gone revealing the Imp's real face. Unfortunately most Imps disappear before that time and are not seen again unless they've stolen another Imp's mask through unsavory methods similar to murder and/or just plain thievery.
