Walter had told Joachim that becoming a vampire would freeze him in place, unchanging for all time. It was only the first lie the old bloodsucker told, and the one that was easiest to disprove - in retrospect, that probably should have been a hint.
But Walter's dust now, and Joachim survives, and his name and form and destiny are his own.
Castlevania: Lament of Innocence, Joachim Armster
But Walter's dust now, and Joachim survives, and his name and form and destiny are his own.