(7x25) Nurbal Enemy: Part 3, Episode 1
As the united forces of the Quelouvan Alliance grow closer to pushing the Berol back through to the wormhole bridging their patch of the wormhole network with the Ehrban's, the Berol respond with a new tactic meant to close off the option of just shutting down the wormholes as was done in the first galactic war. They launch a series of heavily armored high speed carrier ships that penetrate deep into many star systems and, when their armor is finally breached, release the fleet of attack ships that they contain. This effectively flanks the Ehrban forces on many sides, drawing their attention away from the chokepoint they had been forcing the Berol back into, allowing even more of those penetrator ships to breach their lines.
Scrambling to find some weapon with which to defeat the Berol, a project is begun to quickly reactivate the portals in the other direction of space, searching for the original homeworld of the Asiron, hoping to find some of them who still survive there. They find the Asiron homeworld, but it is uninhabited except for a number of primitive species. There is, however, one wormhole leading out of the system, that is sealed from the other side, and the Ehrban hope that more Asiron somehow live on the other side of it.
Instead, while they debate and prepare for a possible sublight expedition to the other end of that wormhole, it opens from the far side, and the ships that come through attack them. Not knowing who these attackers are, possibly some other offshoot of the Berol, they counterattack. After a brief battle that spills into the other star system, an Asiron ship arrives at that star system, and clears up the confusion. The aliens are humans, the "adopted children" of Keius, only now instead of barely-sapient primitives they are far more advanced, some of them on par with or even in some ways exceeding the Ehrban themselves.