Robert Morbidus is the self proclamed True Living Vampire, who had a desire to kill all in his path before he was convinced by Shadow to control his anger, before setting out on a quest to find The Dark Blade. In short he is a sadist who will not leave the ring unless he has had chance to feed on the blood of others (even going as far as ripping apart a referee once a match was over).
His new 'toy', The Dark Blade, makes him a fierce opponent, since it will do ten times the damage of a normal blade.