Environment: Any land? "A castle floating in the wind" isn't a standard environment type.
Hmm… I guess so. While Ahi's castle might float over the sea more often than it does land he doesn't live in the water.
Is "Any sky" out of the question?
Any thoughts on tactics? I was going with something like "Ahi uses his gaseous form and ability to control the winds and weather to great effect, preferring to deal with his opponents indirectly when possible." Something simple, like Rahab has.
The original entry mentions him using gaseous form to get behind an opponent so I guess we should mention that.
The steel dragon is an incredibly clever combatant who prefers to deal with enemies indirectly. He uses his ability to control the winds and weather to great effect, often driving away intruders without then ever seeing him. Ahi tends to use magic and breath weapons in combat, although he is not adverse to melee. He often uses his gaseous form ability to hide in clouds or mists, then maneuvers around to attack his enemies from an unexpected direction.