Halsin would be concerned to hear that he would have to spend any of his time here sick. So much so that he would offer to heal him if needed, if possible.

They are associated with the three main factions here. If you go through the Dryad portal, it will take you to the Grey Ward. Dryad is more nature based, on the main land it seems.

Going through the Sylph portal will take you to Heaven’s Bow, which is a floating city up above. Unsurprisingly, Sylph is more air based.

Going through the Undine portal will take you to Salt Spire, an underwater city that is protected by a bubble. Sylph is water based.

Keep in mind, this is all… Halsin paused with a chuckle. Watered down into a shorter explanation. Too much writing otherwise.