Lofty, superior, and detached.
Example:
The mafia don's manner grew increasingly olympian as he aged, but the old-timers could still remember when he was a hotheaded young thug.
The Greek gods lived high atop Mount Olympus, which allowed them to watch what went on in the human realm below and intervene as they saw fit. But they tended not to worry much about the affairs of these weak and short-lived creatures, although they did insist on being properly worshipped by them. We American voters sometimes feel that Congress treats us in an olympian manner as it determines how our money will be spent.