The Laser Thorn Energy Net is a kind of trap used inside the Cloud Tombs of Praxius.
A Laser Thorn Energy Net was installed as one of the traps inside the Cloud Tombs of Praxius in order to protect the ruins, together with a set of Ion Missile Turrets on their surface and squads of killer drones inside the tombs.
Nebula successfully infiltrated the tombs while Quest for the Orb seeking the Orb under Thanos' request, who believed the artifact could have been hidden on Praxius IX. However, as she was ambushed inside the tomb by the killer drones, she activated the Laser Thorn Energy Net and was trapped by it.
Even trapped inside the net, Nebula wanted to fight the killer drones, but she was saved by Gamora, who arrived and destroyed the drones, but left Nebula trapped under Thanos' explicit orders.
Thanos wanted Nebula to escape for herself and turn her weakness into strength, so Gamora offered her a metal blade knowing it could not cut the energy net. Given no other means of escape, Nebula decided to cut off her own arm and part of her face in order to survive, leaving her severed limb trapped in the energy net to be replaced by a cybernetic arm.
Impenetrable and inescapable, stripping flesh and mangling bone as the thorns burn deeper, Laser Thorns cannot be cut with metal blades producing a particularly deadly form of snare.