I’ll outline my understanding of how Ghosts, EXO’s and resurrections work.
Ghosts: Can bind to a single guardian (Seguira seems to bind with our guardian, but I wonder if that is only because she is sharing a shell with our ghost?)
Reasons I believe this: If ghosts could resurrect anyone they want, why would any Guardian ever die? Why would each guardian in a fireteam bring their ghost with them? Literally, bring a couple ghosts for resurrections and leave the rest behind so that they are “safe”. If your ghosts could resurrect multiple people then why would our ghost search so long to find us? Just keep resurrecting people until you find the one you like?
EXO: Machine that has a human mind embedded into it’s circuitry. Reboot to counter Condition Dissassociative EXO Mind Rejection (thx Byf) Therefore we can’t transfer a mind from Cayde’s dead body to a new EXO.
Reasons I believe this: Why would EXO’s need a ghost if they just can be destroyed and recreated? The ghost must be able to resurrect that inner personality to the same state it was before the destruction. Also apparently ghosts can reconstruct machine frames as well as flesh?
With these understandings, I say Cayde-6 is dead and there is little chance of Cayde-7. Cayde’s ghost is shot and killed, and his body is also dead so no resurrection and no personality transfer are possible.
Please send me any info that contradicts or supports my assumptions. @djkouza on Twitter.
Update: Just watched Byf’s video: https://www.youtube.com/watch?v=tdCeRPUbjI8&feature=youtu.be