Octaria System, Euronia II.
The Ork Fleet led by Sneaky Boss was not making good progress.
Four World Devourers, a million-strong Tyranid Fleet, and a planet fortified along with its three moons.
Against anyone other than Slick's Screw Clan, a defensive line like this truly would have been a Wall of Sighs.
The Dimensional Rumble Cannon, Gauss Mega-Cannon, C'tan Shard Cannon, and Dio Cannon were all devastating weapons capable of destroying Tyranid Bio-ships across vast areas.
But the Great Devourer had too much biomass, and its Tyranid Fleet was far too vast. Even if every shot from these devastating weapons took out huge numbers of Tyranid Bio-ships, fresh ones always moved up to replace them.
And as the Great Devourer learned more about these weapons' performance, attack ranges, and other parameters, its countermeasures became increasingly precise.
Every time Sneaky Boss fired the C'tan Shard Cannon, for instance, he found that it killed fewer Tyranid Bio-ships than before.
Sneaky Boss isolated a precise frame from the attack footage. In it, the C'tan Shard Cannon's intertwined gold-and-green lightning cooked a Tyranid Bio-ship. According to its design, the beam should then have jumped to another Tyranid Bio-ship.
The distance was definitely short enough, but the energy beam vanished without triggering a chain reaction.
Sneaky Boss put the image onto his device, magnified it further, and broke it down into a dozen or so frames. After analyzing them, he found the problem: the dead Tyranid Bio-ship had released a magnetic field that distorted the energy meant to trigger the chain reaction, drastically shortening the distance over which it could jump.
"They're evolving too fast..." Sneaky Boss sighed. He had no idea how deep the Great Devourer's gene pool ran, but seeing the Tyranid Bio-ships evolve in so many different ways and render his trump-card