If you're wanting your magical flight to be something akin to fast travel, then that isn't possible.
Let me put this in an example, let's just say you could magically fly about 80 miles per hour. (This is in the ballpark of the flap speed of some of the fastest birds in the real world.)
And say you could travel 5 minutes before needing to land and take a breather, at such a fast speed... That's still only about six and a half miles of actual distance in five minutes.
And while the specifics on how large things the world is and how long it would take to get places is left hush, to note Sigrogana is considered a continent.
So I think it's fair to say that unless you're already pretty close, using magical flight to appear at or near Tannis to intercept a Black Beast attack or what have you isn't in the cards.
Let me put this in an example, let's just say you could magically fly about 80 miles per hour. (This is in the ballpark of the flap speed of some of the fastest birds in the real world.)
And say you could travel 5 minutes before needing to land and take a breather, at such a fast speed... That's still only about six and a half miles of actual distance in five minutes.
And while the specifics on how large things the world is and how long it would take to get places is left hush, to note Sigrogana is considered a continent.
So I think it's fair to say that unless you're already pretty close, using magical flight to appear at or near Tannis to intercept a Black Beast attack or what have you isn't in the cards.