An Id is the identity or soul-like essence of a folk or folklore. The term refers to Sigmund Freud's three-part concept of the psyche. The "id" is the unconscious or instinctual part of the psyche. Since the souls that make up the folks have not found peace, they are ruled by the unsettled emotions that caused them to remain in the Netherworld. Each folk has a unique Id that you must absorb before you can use it. This is also the only way for Ellen and Keats to gain experience to Rank Up.
Blue Id
Blue & Red Ids[]
Valid attacks cause the Id to temporarily appear in a light blue above the folk, invalid attacks will not show an Id. Any attacks blocked by a guard/barrier will show a red pulse and play a clashing sound. However, sometimes only folks with certain elements will be able to cause valid attacks.
Red Id
Once you have attacked the folk sufficiently, a red Id will remain above it for a short time. Its at this point you can absorb the folk's Id.
Absorption[]
When you first encounter a Folk, you can see a darkened out image of that folk in your folk menu. To acquire it, you must absorb its identity by attacking it with the folks you have already captured. Please note that only folks in front of the character will be absorbed (180° from left to right). If more than one folk is in front of you and showing a red Id, you can absorb all of them. Absorbing multiple Ids increases your experience multiplier, helping you rank up faster.
There are five ways to absorb depending on the folk and the character you are controlling. All five methods are initiated by holding the 
button and pulling the controller up. This will automatically absorb most Ids and is known as a 'quick absorb'. Folks that only need the 'quick absorb' can be absorbed simultaneously by holding down and leaving a small pause before pulling the controller up.
The other four methods will cause the screen to zoom in so you can better view the folk, the colour of its Id and any instructions there may be. You can view the in game tutorials again by pressing 
on this screen.
These are the other four methods;
Folklore always required a 'mixed absorb', using two or more different methods before you can finally absorb their Id.
During all five methods it is important to remember that the other folks will not stand idly by, and if they hit you, the absorb will be canceled. The absorb will also be canceled if, the bar is reduced to zero when you are too slow or make mistakes.