Singularity

 is an active item.

Effects

 * Spawns a black hole that sucks enemies, bullets, and items into it.
 * Enemies in the black hole take damage.
 * Bullets sucked into the black hole are destroyed.

Trivia

 * This item may be a reference to the Gersh Device found in the Zombies mode in Call of Duty: Black Ops.
 * The Hellhole synergy is likely a reference to the movie Event Horizon in which a crew of astronauts attempting to find a missing spaceship find a portal to hell through a machine that uses artificial black holes.