I've been working on converting the Ghostwalk setting from 3e into 5e and I've hit a few stumbling blocks. Specifically with Ghost Powers and The Calling. I have some ideas on how to proceed with them but would like to get some other thoughts on them.
For those that aren't aware, Ghostwalk was a setting that focused on Manifest, a city that literally sits on the entrance to the Afterlife. People who die can allow themselves to pass straight into the Afterlife or they can decide to stay longer and become Ghosts. Since ghosts within Manifest are fully... um... manifested they are able to interact with the world around them like anyone else. This creates a city where the living and the dead "live" side by side.
It is important to note that these are not your average DnD ghost. They are not mad or doomed to haunt a certain place. They are still the person they were when they were alive, only without a body.
The bonus for players was that characters that died would come back as ghosts shortly after dying and could keep playing. They could have themselves brought back to life with greater ease, or they could remain as ghosts and learn ghostly powers like possession or shaping ectoplasm.
The one of the downside of being a ghost was that you could not level normally but had to instead take levels in one of two ghost classes, the Eidolon and Eidolancer, who focused on increasing your ghost powers (which could be taken as feats). Characters that have more Eidolon/Eidolancer levels than normal class levels would succumb to something called The Calling as they could no longer resist the pull of the Afterlife. Characters could trade in those "ghost" levels for regular class levels if they wanted when they were brought back to life in something called Life Epiphany.
I want to replicate the Calling but I don't want to create an entire class around something as specific as being a ghost. I also want to allow access to ghost powers, which I also need to convert, but I don't want to require that players take them as class features or feats.
Rambling out of the way, here's my current idea.
Characters track the XP they get while they are ghosts separately from when they are alive, though they add the two totals together to determine how much XP they have and when they will level. The character succumbs to The Calling If the XP that gained as a ghost is ever equal to or greater than that xp he has gained while alive.
Ghosts who are brought back to life can experience a Life Epiphany. This causes 25% of the Ghost XP they have collected to be converted into Living XP.* A character can only experience one Life Epiphany per level. The more limited nature of the Life Epiphany is there to keep the Calling from becoming a paper tiger but still allowing the player a way to shed the extra XP.
*Example: A PC has gained 1500xp while alive and 1000xp while ghost. They are brought back and 25% of their Ghost XP (250xp here) is converted to Living XP. The PC now has 1750 Living XP and 750 Ghost XP.
Ghosts must use downtime to learn Ghost Powers. The amount of time spent training varies depending on the power but they can cut the time in half if they get training from another Ghost. Characters can choose to forget one or more of their Ghost Powers when they are raised from the dead. Time that was spent training on a ghost power the character forgot counts towards training in a new language or tool use. A character who does not forget their Ghost Powers reduces the amount of Ghost XP converted during a Life Epiphany to 15% due to their becoming less tied to their mortality.
Any suggestions would be appreciated.