Drax calmly observed Max's mental state and attitude and felt satisfied seeing him progress.
Today Drax finally felt as if he was truly serving a lord and had not merged with some imbecile kid.
When he had just merged with Max a few years ago and had taken a glance at his memories, he saw a weak man who did not have the guts to achieve his dreams.
Back then, he had to force Max to kill his abusive ex-girlfriend because it was necessary to temper his mentality.
At the time he could remember the trembling teenager who was reluctant to take a human life, which was in stark contrast to the man he was today, who emotionlessly killed Zogaroth just because he might someday leak the secret of the sealing method to someone else.
It was a gradual change in his temperament which had been kickstarted ever since he merged with Drax and killed Sophie, however the speed was exaggerated once he became a primordial vampire.