Sorry, but the Shadows from Babylon 5 are not hostile at all! They act in the request of other species to attack, but for their own they do not try to annihilate, enslave or subjugate. They act like Mephisto, offer possibilities and some may take it or not. All in order to follow the natural way of selection, contrary to the Vorlons who interfere with almost every race to set up their, in their thinking, ideal universe. For that here should be the Vorlons and not the Shadows even when it seems not quite right at first, but later in the show it should be clear about their intentions. Also the Shadows only act because the Vorlons do, so they are quite passive and only try to prohibit the manipulation of the Vorlons.
Just my 2 cents.