In the storyline, Whisper Glimmers are partial Glimmers summoned using pages that were physically torn out from their lorebook. As Glimmers need to be formed directly from a lorebook, Whispers are the result of an incomplete summon, resulting in their ghostly appearance. As such, they require their Illumineer to boost them to become fully-formed Glimmers.[1] These Glimmers come with the signature ability Boost to trigger new abilities or make themselves stronger.[2]
As opposed to their complete selves, Whispers have a translucent, wisp-like form, where they look like they are trailing off from the page they come from. These wisp trails follow the physics of the ink they were summoned from, giving them a colorful aura that corresponds to the ink's attributes.[3]