Hostile and Allied Fine Points

Aid still works on a Hostile player: it can't improve the relationship, but you may take one of their crafted items. Forming a Coalition with a Hostile faction moves it back to Indifferent. If you take more hits on an Ally's warriors than on your own items in a battle, that faction becomes Hostile. If moving or fighting with Allied warriors means a card is owed to the Alliance, the Vagabond gives it.