The System Lords expansion may be named for the Goa'uld, but they aren't the only baddies getting a nice boost in the set. Fans of the Replicators are sure to like this card:

Replicator obstacles rely on counting other Replicator obstacles for their effects, so the usefulness of Approaching Swarm is plain to see. For just 3 power, this and Corrosive Spray will destroy two support characters after a failed mission. This card combined with Big Bug gives you an impressive +4 difficulty at a Combat mission -- again, for just 3 power. And while you might not want to stock too many Combat-only obstacles in one deck, it's awfully nice to follow Approaching Swarm with Overrun.

And that's just looking at the Replicator cards from SG-1. With System Lords, the number available more than doubles. And while not all of them can be combined with Approaching Swarm (because not all of them have a Combat difficulty rating), it still adds up to an impressive array of potential card combos and plenty of fun for fans of the Replicators.