Each Nightmare possesses formidable abilities designed specifically for use in extreme combat situations, which would allow them to fight more effectively with enemies equipped with power armor or survive longer against NH-27 and the NH-28 Nekovalkyrja models – in addition to any similarly dangerous models that may be developed in the future.

The Nightmare's biological make-up is extremely robust and experiences an almost non-existent rate of natural cell death. This means that Nightmares need not eat for months at a time unless they suffer injury – though they often do eat for the pleasure of it. In the case of severe injury, they would need to consume biological materials and certain metallic elements to replace lost body mass utilized to regenerate their bodies wounds. With fairly basic NMX medical supervision a Nightmare would effectively be immortal – that is, they would likely never succumb to death through old age.

With the genetic and hemosynthetic alterations to which they have been subjected, Nightmares also attain physical maturity at a much faster rate than NH-29. NH-29's typically require three or so months to reach adult stature, whilst a Nightmares growth is solely dependent upon their intake of food immediately following their birth. Provided with sufficient food, a Nightmare can reach adulthood in a matter of a few days. Artificially produced Nightmares are all full-grown, like their NH-29 counterparts.

The Nightmares can utilize specialized organs located within the palms of their hands to generate scalar field distortions as a means of offense. Use of this ability is draining, and after a time a Nightmare will require sustenance in order to recover their energy. Two kinds of attack are possible.

High-intensity scalar energy pulse intended to kill.

• Damage: Tier 3, Heavy Anti-Personnel/Tier 3, Heavy Anti-Personnel
• Range: 200 meters
• Rate of Fire: Twice every three seconds (Once per each hand)

Low intensity pulses intended to stun, rather than kill enemies if it suits the Nightmares purposes.

• Damage: Negligible - Renders unprotected enemies unconscious
• Range: 200 meters
• Rate of Fire: Twice every second (Once per hand)

Through an NMX reinterpretation of Nekovalkyrja Hemosynthetics the bodies of Nightmares organically synthesize metallic compounds for incorporation into their own physiology. The armored carapace, bones and individual cellular structures of Nightmares make good use of these extremely durable metals. This makes the natural skin and body plates of each Nightmare highly resistant to external damage.

A Nightmare has similar physical endurance to the Mishhuvurthyar Crab – though due to the obvious difference in size, they aren't quite in the same league. The most resilient regions of a Nightmares body are those protected by spiked carapace, including the head with its reinforced skull (though a non-fatal head-shot can still result in complete blindness or an otherwise debilitating injury). Regions of exposed flesh are more susceptible to damage, but are still highly resistant due to sub-epidermal protective layers and the their overall structural composition.

The musculature of the Nightmare type has been structurally reinforced with a mixture of organically synthesized metallic compounds and dense chains of carbon nano-fibers, vastly increasing its endurance, density and capability. Generally the muscles of a Nightmare appears sleek unless they are under heavy exertion – in which case they can appear to expand rather dramatically. A Nightmare can lift a metric tonne (1,000 kg or 2,205 lbs) overhead with ease whilst experiencing 1G. With effort Nightmares can lift overhead approximately 2,000 kg (4,410 lbs) in 1G for a limited duration (about 20-30 seconds), before experiencing any significant strain. The armored blade-like talons and clawed feet of a Nightmare when utilized in combination with their monstrous strength enable them to impale or even bisect unarmored enemies with a single blow. Whilst power armor offers a measure of protection, it cannot last indefinitely in close-quarters combat against a Nightmares claws.

Like normal Nekovalkyrja, Nightmares have inherited incredible agility and a sense of balance far exceeding what is possible for an unaltered human. Additionally, thanks primarily to their augmented musculature Nightmares are capable of extreme bursts of speed on foot. This can be utilized to considerable affect in order to close the distance with enemies in combat and unleash disconcertingly sudden and powerful melee attacks.

A Nightmare is able to recover from wounds at an extremely accelerated rate, even when compared to the NH-29. Minor wounds disappear in a matter of minutes, whilst severe injuries like the loss of a limb can be restored within an hour or so – assuming that the Nightmare has sufficient stored biomass to recover from the injury. In the event that they do not have sufficient bodily stores, the Nightmare will need to consume biological and inorganic materials sufficient for the task. It is often the case that Nightmares will cannibalize ally and enemy soldiers or even other severely injured Nightmares in order to recover more quickly from their injuries and return to their full strength.

In some cases it is possible for Nightmares to regenerate after having been killed from severe head trauma if their internal hemosynthetic ability is able to redistribute enough materials from other regions of their body. This process usually takes hours and afterward they will be temporarily weaker and highly disoriented as much of their original personality, memories and knowledge will be lost due to the injury. However, basic NMX knowledge and an aggressive nature is hard-written into their genetic code – meaning even a reborn Nightmare would be immediately hostile. Because of this fact, it is recommended for enemies of the NMX to completely incinerate Nightmare corpses or otherwise make certain that any bodies in their possession won't suddenly come back to life and run amok.

The vision of a Nightmare is incredibly acute and at will they are expand their sight to see at extreme distances hundreds of times beyond the human norm. They have near perfect night-vision and are also able to visualize at will most of the electromagnetic spectrum in their surrounding environment, allowing them to physically perceive ambient sources of heat, radio waves and other EM phenomenon. Their hearing is just as acute as that of a normal NH-29, and allows them a 3-dimensional spatial sense of sound sources in their vicinity.

The Nightmares physiology also includes additional artificial sensory organs designed to mimic the sensory capabilities of advanced mechanical devices. This includes a passive ability to sense and interpret ambient radio, subspace and tachyon transmissions. They can also actively sense out enemy vehicles and power armor within a range of a few hundred kilometers that aren't operating under heavy stealth or jamming.

The Nightmare shares the Nekovalkyrja's ability to store and organize information in a computer-like manner. They also have the ability to send information with their telepathy – to other individuals as well as certain mechanical devices.

The telepathic abilities of a Nightmare are more powerful than those of a normal NH-29, allowing them to send psionic messages up to a distance of nearly 2,000 kilometers (1,243 miles) as easily as they would with vocal speech. Like their genetic cousin's, a Nightmares computer-like mind can encrypt their messages and make them virtually undecipherable by anyone but the intended recipient. They can transmit text, audio, and/or video.

Nightmares also have a form of psionic ability which allows them to induce a range of terrifying, though physically harmless auditory and visual hallucinations in those that are nearby. Typically such hallucinations are used to invoke feelings of fear and paranoia, such as grotesque imagery, movements out of the corner of ones eye, sounds with no visible source, etc. The viability of this kind of psionic attack has become limited due to the use of the Psionic Signal Controller in power armor, ships and bases. When unprotected by such technology, the ability is mostly utilized to invoke terror and panic in their enemies.

The Nightmare's share the Neko and Mishhuvurthyar ability to manipulate gravitational, electrostatic and magnetic forces to allow their bodies to self-propel themselves in environments of zero to two gravities. They can hover around up to speeds of about 320 kilometers (198.8 miles) per hour in any direction.

The Nightmares have retained the NH-29 capability to produce holograms in close proximity to their bodies. They are capable of creating exceedingly complex illusions – completely changing their external appearance in order to disguise themselves as ordinary Neko, humans or even other races. They are also able to use their holographic abilities to render themselves effectively invisible.

In order for their holographic illusions to function, a Nightmare must remain conscious.

A Nightmare is able to reconfigure the size, type and number of tentacles present upon their backs as needed through internal hemosynthesis over the course of an hour or two. They can grow additional tentacles by utilizing internal biomass or through consuming the needed materials. Alternatively, they can reabsorb the materials of their tentacles into their bodies if they are no longer required or they need to heal injuries.

Each Nightmare can change a tentacles type into any of the varieties available within the Mishhuvurthyar Tentacles. They can reach a maximum length of about 2-2.5 meters (6.5-8.2 feet). The maximum number of tentacles a Nightmare can support is typically around twenty-four.