The weapon consists of the GKZ-45 on the left, which shoots yellow clouds of energy that slow down zombies, and the Ray Gun Mark III on the right, which shoots thinner versions of the Ray Gunprojectile which do not cause splash damage. Running through the cloud will cause the player to run quickly much like the Overdrive specialist ability or the spores shot by the KT-4 on Zetsubou No Shima. Similar to igniting gas with a spark, shooting the yellow energy with the Ray Gun Mark III will cause it to become a black hole similar to the ones created by the Gersch Device and the Apothicon servant, but with much lower damage (one-shot kill until round 25-30), smaller range, and shorter duration. Rather than being sucked into the black hole, zombies affected will float up and dissolve into a purple mist, similar to the effect of the Wave Gun, Storm Bow and Skull of Nan Sapwe.When upgraded in the Pack-A-Punch, it becomes the Maelstrom of Eris. The weapon carries five rounds in the GKZ-45, 30 rounds in the Mark III, and initially 210 in reserve, although it will receive 215 when the player receives a Max Ammo. The upgrade appears red, provides additional ammo, and increases the duration, range, and damage of the black hole effect. The Ray Gun Mark III upgraded will fire red beams, similar to its predecessors, but the GKZ-45 continues to fire yellow balls of energy.