Voidstone

Voidstones are quasi-living entities formed from lingering fragments of the void.

Despite their resemblance to Brimstones, Voidstones do not have an immediate offensive capability. They emit a pulse that applies a limited-duration invulnerability shield to nearby enemies; if there are no other enemies, excluding another voidstone, to protect and are not destroyed first, they will self-destruct, emitting a red, damaging wave around themselves.

As of Chaos Update killing a voidstone will remove its immunity buff from other enemies.

While the Voidstones that appear upon the Barge of Death in Asphodel are considered Dire Voidstones by the Fated List of Minor Prophecies, they have no special qualities to them, not even armor. With Middle Management active, however, they're replaced by a singular giant Voidstone with much more health and plenty of armor.