Petrarius is a thrall borned and raised. Submisseve and obedient through and through. He has never given any problems and thus became a favourite snack for a few vampires in the von Carstein house. In the end Wilhelm von Wither couldn't leave his favoutrite snack behind and brought Petrarius along.
It seems Petrarius is taking up the legacy after
Mockus
Petrarius, have indeed taken up the legacy after
Mockus
and is now in all games helping the vamps to stay their immense blood lust.