During the events of the Time Heist, Nebula was interrogated and tortured by her 2014 self. Trying to plead with 2014 Gamora by telling her about her fate, Nebula was knocked down by her younger self. 2014 Nebula began to threaten her future self and used her energy dagger to remove the orange accents from 2023 Nebula's face in order to disguise herself when traveling to the future.
Nebula's Energy Dagger is highly durable and sharp being able to pierce through 2023 Nebula's cybernetic facial prosthetics. The dagger also can emit a blue light on the blade, enabling it to be used in dark areas.