The Hero's Path

Come on, "useless" – it has a high Intelligence stat, which is great for scouting – I win half my battles with it by casting Slow, Sleep, Berserk, Dispel, Charm, or Wall of Swords first – choose whichever is most appropriate. As for "Silent Stalker," you just have to take what you get.
And how is it implemented in Aglaia's campaign, in the final mission? I think the land is revealed as you move, but the sea isn't.