Ghosts can only have one Guardian, and cannot change to a new Guardian. Each Ghost has one ideal match for a Guardian, but they have the option to revive someone else. However, once a Guardian is revived, this choice is irreversible. There are [b]many[/b] accounts from Ghosts who lost their Guardians -or are still searching for them- that directly confirm this information (several of these are excerpts from Ghost Stories, but there are others, including a direct quote from our Ghost and more from the nine Ghosts who Orin spoke to when searching for the Nine). I see people mentioning Saint-14, but that’s wrong. Our Ghost only met Saint-14. Many people also mention Jaren Ward’s Ghost and Shin Malfur. This is part of a huge misconception. Jaren Ward, his Ghost, and Dredgen Yor all saw the Light in Shin Malfur, confirming that he was already a Guardian (this is why they were so interested in him), meaning he was most likely the infant from the Confession of Hope excerpts in Ghost Stories (seriously, read those), or a similar case. After Jaren died, his Ghost went to Shin and said something to him (most likely telling him that he had the Light). All other lore directly confirms that it was not possible for Jaren’s Ghost to become Shin’s Ghost. Also notice that after Jaren’s death, we have seen absolutely no sign of any Ghost with Shin and Shin has not been harmed or killed (to our knowledge). Edit: that last bit about not seeing a Ghost isn’t really important, since Jaren’s Ghost could still be with Shin. Also, during Cayde’s death, our Ghost saying he can’t do anything to help suggests that Ghosts mat be able to heal (but not revive) other Guardians, at least a little.