I'm not sure whether you call it a bug or a feature but from time to time we have had the conversation regarding translating characters between systems. This is not an unusual way of spicing up game play and campaigns that have been run for a very long time. It's also a really fun thing to try out as its a sort of cooking by numbers when you are actually missing some of the digits. Some systems, such as the recent Strange, actually revolve around swapping universes but the same can be done in principal by using any two systems, so by simply hacking at the respective RPG character rules and rolling up an equivalent using adjusted mechanics you should be able to migrate a personality. Ok, there may be issues drawing up a droid in Deadlands so some creativity may be required but I have always seen it sort of work albeit with some compromises.
However, my memory is cast back about 30 years when we passed a fun evening using the old Timelords system. Not to be confused with Doctor Who, the narrative begins at the end of time with a race called the Designers who have to invent a temporal matrix in order to survive - time paradoxes were "solved" by jumping to another universe. However the system includes mechanics for rolling up oneself; reality being just another system of course.
I don't remember much of the details other than holding out a weight for as long as I could to generate my strength stat. There was an IQ test for Int, or you could use your school qualifications if available, and also I remember a weird balancing act to determine Dex. The list of skills is almost directly drawn from professional abilities and hobbies. I didn't have a pet at the time, so no familiar but oddly enough roleplaying was a skill I had to add to my own roleplaying character sheet - the number of years spent within an interest or capability determined the in game rank. Nevertheless after a drunken evening I remember being pleased with the result but overall I was less surprised to find out that as a party, we were all a bit crap. Well I guess students start at first level, but as a wizened master now I would be keen to try this again as my miserable old git score would be off the charts.