A congealed poltergeist formed from the discharge of large amounts of negative energy (hate, fear, etceteras), NBEs exist to feed on strong positive or neutral energy. A constant hazard to magicians and psionicists, weak NBEs are relatively easy to contain or dissipate with marginal training. The stronger the energy, the stronger the NBE and the more effort or time it takes to dissipate. At BMC, the Templar use biomagnetic concentrators to collect and contain this type of energy, releasing it only in the most dire of emergencies.
NBE appear to be unique to the pocket universes and Veils of Earth.