Since the collective trauma of the land in the initial splintering of the five regions, The Splinterlands took on a level of cosmic energy the likes of which are incomprehensible outside the physics that are apparent within their universe, as well as not as apparent to the untrained "Third Eye."
That being sight of additional happenings around one's environment that isn't apparent those who don't have the more supernatural third eye linked to this sight. During the time of the great chaos and splintering that caused this cosmic rift in the Splinterlands, the mass death and chaos that ensued become overwhelming to those that inhabited the lands. From a very simple complexity they arose into far more complex beings in this super morphing period. Common birds became monsters, common fish-water life became these monsters as well. All throughout this "Super Morphing Period" the living creatures of the lands became more and more hideous and frightening. Then after several attempts by "Eusummoners," (later called Good or Peace Summoners) the monsters began to fulfill their destiny as creatures of war. As time went on the Eusummoners became summoners of war, destruction, and perilous hope that gripped the land. Eventually the Eusummoners were finished off, and the current Summoners of War currently reign supreme.
But during the early cataclysm of the splintering, the mass death, and the fear collected into an energy that turned this collective chaotic event into a quasi-living specter, or apparition that is so frightening to these monsters with the extra vision that it renders them helpless, stunned, so terrified they emit an internal poison the likes of which has yet to find a cure for this blackening destroyer of all energy the monsters of the Splinterlands can posses.
There have only been a few characters that have shown some immunity to it, though not complete immunity. Roughly half of the time the following characters have displayed an immunity to this dreaded disease that leads to inevitable death to follow. The characters that are not effected by this illness have special spiritual features to them, that of more peaceful, and more deeply spiritual beings linking them to the prior spirit that took them back to the ancient, Pre-Splintering period.
These include (cards that have in their name) Shamans, Kings, Sorcerers/Sorceress, Seers, Knights, Healers, Defenders, and Enchanters/Enchantresses so far. The only immune card to this attack is the Angel of Light, having the foresight of spiritual maximalist intentions, that foster this immunity-and to what some say in the lore, an ability to heal the stun malady that overtakes the monster in battle when confronted with these horrifying "Doppelgangers of Terror" to these monsters. Only the Angel of Light has the ability that can cleanse the monster of the poison and/or stun that haunts these living creatures of terror.
These Doppelganger apparitions began when the Dark Energy Crystals were being manipulated by the rulers and lords of the splinterlands causing them great power, but creating this horrifying and centrally opposition forces to their mayhem and destruction of the others. Or so the legend is written.
Both pictures above created with this photo editor and a standard Alpha Skeleton Assassin