Are you sure he spawned there? Air Elementals have flying now, they can cross water.

There is a bug or feature that allows the airshrills that are with the elemental to fly as well. He probably flew across the sea...

"So I apologize if this screenshot is massive, I'm just getting used to image uploads"

its fine!

"What I would like to point out is that this air elemental and his friends spawned in the square where they are currently pictured, completely randomly"

as the others said, are you sure they spawned, looking at your minimap it seems likely the air elemental "carried" the airshrills over the body of water (when a monster group have an air elemental, the whole monster groups is flying).

"high level monsters from far, far away (sometimes places the player hasn't even explored) deciding to leave their lairs and home in on your cities is getting very old."

Yes that is really getting old, being ambushed in my own territory from earth elementals, fire elementals, dragons and whatever else the widlands all over the map used to contain is mildly annoying.

Edit: Broken Quotes

Sincerely
~ Kongdej