Nokkers

Knockers (ノッカー) are unknown creatures that were created to impede Fushi's progress in preserving the world. The Black Hood named them "Knockers" because they "pound on the doors of paradise, seeking it's destruction."

Description
Knockers are creatures that were created by an unknown being for the purpose of hindering Fushi's progress in preserving the world. A Knocker's main form resembles long, presumably sharp, vines. However, they adapt to their environment and take on various other forms - forms stolen from Fushi. When in the forest, the Knocker took on the appearance of vines and leaves. At Rynn's house and on Junanda, it took on the appearance of rocks.

Abilities
(more to be added)
 * The Knockers have the ability to steal Fushi's forms, along with his memories of that form. For example. when the Knockers steal March's form from Fushi, he is completely unable to remember her. He isn't even aware that anything was stolen from him.
 * They adapt to their environment and are constantly studying and learning about the world around them. When Fushi first encounters the Knockers in the forest, it is made up of vines and leaves. The next time he encounters one on the island of Junanda, it is made up of rock.
 * The Knockers are able to control a person's body, whether they are alive or dead.