Could be wrong but normally a ghost cant die unless the light cant connect with it and it is destroyed. Also something that would drain the light like weapons of sorrows and other hive tools. If a ghost is lets say shot or damaged by something that doesnt cut the connection with the light it will just get damaged but can be repaired. Like sagira and how her shell was damaged but was brought back. So in the travelers case its damaged and cant do much but is still there and healing. i do believe its power could be passed on though maybe.