Ghost Lord
By 2019, “mysterious invaders” were in the process of taking over the Spirit Realm of the Prime Universe (PROSE: A Copper-Colored Christmas Carol) and others, such as that of the Frost King's Realm. (PROSE: The Winter Quests)
They were described by the Ghost of Christmas Present as alien to the Spirit Realm, and possessing powers beyond any true ghosts; most notably, they were able to drag spirits back into the Spirit Realm, and to create chains which ghosts could not touch. (PROSE: A Copper-Colored Christmas Carol)
History
On Halloween 2019, the Great Ghost's legion tried to evacuate from the Spirit Realm into the Cupid Homeworld, though the invasion was ultimately foiled. Though noting that the Spirit Realm had become compromised in some way, he did not elaborate further within earshot of the Cupids. (PROSE: The Ghosts and the Machine)
In the night before Christmas in 2019, the “mysterious invaders” snatched the Ghost of Christmas Past) and Ghost of Christmas Present as they finished their parts in the Christmas Carol scenario they had been visiting upon Philatel-426, of the Cupid Homeworld. After chaining the two Ghosts in the Spirit Realm, they left them to their own devices, which allowed the Ghost of Christmas Yet-to-Come to dispatch Philatel himself to their rescue. The Three Spirits then departed, vowing to stick closer together to avoid departure — as the invaders seemed to fear Yet-to-Come. When the Spirits returned Philatel to the Cupid Homeworld, they erased his memory of his experiences in the Spirit Realm. (PROSE: A Copper-Colored Christmas Carol)