Geist

Geists are creatures of Grimm that resemble ghosts and are capable of "possessing" and controlling inanimate objects.

The Geist made its first appearance in the "White" Trailer, possessing a suit of armor and forming an Arma Gigas. The first appearance of its true form was in "The Next Step" where it also formed a Petra Gigas by possessing boulders.

Salem is capable of summoning and controlling entities called Shadow Hands, which appear as Geist arms and one such hand was used to replace Cinder Fall's missing left arm after her defeat at the Fall of Beacon.

Appearance
A Geist's base form is a black figure that has bone-like spikes on its back and ribs on its upper body, with long, skeletal forearms and sharp fingernails. Due to its ghostly appearance, it lacks a lower body, instead floating through the air while leaving behind a black smoke trail. Its face consists of Grimm markings on a mask-like bone plate with a single eye.

Powers and Abilities
A Geist is a possession-type Grimm, capable of controlling any inorganic matter it possesses as extensions of its own body. Should it lose any of its limbs, it can repair the chink in its armor almost immediately by simply possessing another object in the vicinity. Its only real vulnerability is its "face", the central segment from which it maintains control of the form as a whole. Once its host object is destroyed or severely disabled, it abandons the body, revealing its base form. The Geist has yet to demonstrate any combat abilities in this form, but it appears to be relatively frail; it was killed with a single shot from Crescent Rose.

Appearance
An Arma Gigas is a suit of armor that has been possessed by a Geist. The "White" Trailer features one that takes on the appearance of a medieval suit of armor with clawed finger tips and pointed protrusions on its helmet, fingers and knees. It stands at least twice as tall as Weiss Schnee.

This Arma Gigas has a very different appearance in the third and fourth chapters of the manga, which explain the events of the "White" Trailer. In these chapters, its helmet is more rounded and has two separate openings, behind which a pair of glowing eyes are set. The rest of the armor also has a widely differing appearance, though both have a medieval aesthetic to them.

Powers and Abilities
The Arma Gigas displays the full mobility of a human, capable of running, jumping, punching and holding objects. The armor itself moves quickly for its size and is shown to be strong enough to wield a sword that is as long as it is tall with only one hand. The material of the armor makes it difficult to damage.

In the manga, the President's Secretary states that its strength is comparable to that of a "mecha-suit" and that it is three times stronger than the original model. In fact, the President's Secretary's description of its strength makes it clear to Weiss that both her father, Jacques Schnee, and the President's Secretary believe that she has no chance of defeating it.

Appearance
A Petra Gigas is formed when a Geist possesses rocks. The one seen in "The Next Step" consists of gray boulders, which form a central body and four levitating limbs. Through the Geist's influence, these boulders gain red vein-like markings. During its fight against Team RNJR, it loses one of its arms, which it replaces with a tree trunk.

Powers and Abilities
Through its stiff and slow movements, the Petra Gigas utilizes its enormous mass to deliver heavy attacks. The rocks that form its body are virtually immune to slashing attacks as well as lightning and fire Dust ammunition. Because the rocks are not physically connected to one another, it is possible to weaken the Petra Gigas by forcibly removing its limbs. However, it can possess nearby objects to replace its lost limbs, as seen in "The Next Step". In that episode, a Petra Gigas turns an old tree trunk into a new arm, but without an elbow-like joint, the tree arm proves to have less mobility than the rock arm that it replaces.

Cinder


After losing her left arm in her attack on Beacon because of Ruby Rose's Silver eyes, Cinder was given a Grimm arm by Salem by unknown means. The arm has the ability to stretch and siphon Maiden powers and its claws were able to impale Vernal, leading to her death. Her Grimm arm cannot channel Aura, making it vulnerable to attacks, but it is capable of channeling magic, allowing her to create her weapons. It also gives her a crippling weakness to Silver eyes as seen in the Battle of Haven when Ruby's Silver Eyes attack put her in immense pain.

Salem


In "So That's How It Is", Salem summoned multiple Shadow Hands from the floor to immobilize Hazel Rainart for giving her displeasing information. The arms were summoned through a Geist glyph and a cloud of black smoke, appearing similarly to a Geist but behaving differently.

It is unknown if they share the Geist's power to possess inanimate objects and if they are sentient or just an extension of Salem's Grimm powers.

Trivia



 * Geist is a German word meaning "ghost", or depending on the context, "spirit" or "mind".
 * Monty Oum, Miles Luna and Kerry Shawcross created the Geist type of Grimm because they wanted Weiss to fight a giant suit of armor in the "White" Trailer and had to find a way to make that possible within the show.
 * Petra Gigas means "stone giant" in Greek, and Arma Gigas means "weapon giant" in Latin.
 * A red glyph was used when the Petra Gigas summoned an arm. The same glyph was also used when Salem summoned Shadow Hands.
 * The Arma Gigas from the "White" Trailer is first mentioned to be possessed by a Grimm in Chapter 3 of the manga. However, it is described as being an artificial amalgamation of multiple specimens rather than a single Geist.
 * The Petra Gigas was originally supposed to appear during Volume 1 in the Emerald Forest.