This very idea has been in my mind for some time already!
How i imagine this scenario is:
MC dies.
Meets R.O.B or he did some type of Survey and jokingly chose to DK Meliodas.
He would be reincarnated with body of said Demon King when he possessed Meliodas. Same PL, same abilities with muscle memory, no memory on how to use his abilities and etc.
He could reincarnated in , DXD , ROR or similar setting with Gods ,Demons and Devils.
Now let's say, he was transported into said universe with same status of " Demon King" In other words, he wouldn't be able to exist in Human/Mortal Realm, or it would be destroyed.
Created his own Demon Realm and Demon Race.
And to later exist in Mortal Realm, creates or possess body of someone, becomes great player in shadows.
I can imagine this story already in setting such as DXD, with MC getting buffed to same PL as his ROLE requires.