MBTI Personality Analysis
As an ENTP, Ryuk has a mind that constantly seeks new stimulation, is experience-oriented, and questions rules.
The curiosity and playfulness that come with his ENTP nature make him a figure who initiates events rather than directly intervening in them.
Seriousness and responsibility go against his nature. That is why he can see even serious situations as a source of entertainment.
He is mentally quick and easily bored. That is why stagnation is his biggest problem.
Enneagram Personality Analysis
As a 7w8, Ryuk is driven by a constant need for stimulation, movement, and freedom.
The escapist tendency of Type 7 causes him to avoid depth and stay on the surface, because depth is often boring.
The 8 wing adds power and a disregard for limits to this structure. That is why Ryuk does not just have fun; he also ignores the rules.
This combination (7w8) makes him a completely independent and uncontrollable character, because there is no authority over him.