Jar of Souls

The Jar of Souls is a item in Risk of Rain that creates 1 ghost of every enemy onscreen that fights for you for 15 seconds.

Tactics
Functioning similarly to the Happiest Mask, the Jar of Souls spawns a ghost at the location of all enemies onscreen, who will immediately begin attacking other enemies for you. After 15 seconds, all of the ghosts will disappear, like the ones spawned by Happiest Mask.

This item is most useful in large crowds, especially the crowds that spawn upon activating a portal. Doing so will cause all enemies to spawn a ghost on the player's side, and start attacking the crowds that spawned them. Even more useful is the fact that enemies will only attack the players, not the ghosts, allowing the ghosts to attack fairly freely. The best tactical position to use this item is by cliffs full of enemies, as the enemies will stop at the cliff and allow their ghosts to easily attack them.

Item Synergies

 * Using in conjunction with chains more ghosts to appear, should your ghosts kill other enemies and converting them into ghosts as well.

Bugs
Combined with a large stack of (15-20) and, this item will cause severe FPS drop while facing crowds of enemies if used repeatedly.

It is unknown if this is a bug or not, but the Jar of Souls counts ghosts as an enemy for its purposes; therefore, it produces a ghost for ghosts as well. When used in conjunction with the Happiest Mask, this means that not only will a ghost be spawned for every living enemy on the screen, but also another one for every ghost. This can do immense damage and also be very taxing on one's FPS.

Gallery
Jar of Souls