Battle of Ghodba
When Hive Fleet Moloch invades the weapons testing planet of Ghodba, the Tyranids find that the planet has a vicious bite of its own. Everything from unclassified super-heavy war engines to gatling Macrocannons is employed by the Tech-Priest Enginseers that supervise the planet’s defences, with entire phalanxes of Baneblades and Shadowswords leading each charge against Moloch’s many leader-beasts. Yet though Ghodba’s surface is soon thick with Tyranid corpses, reinforcements cannot reach the planet for months at best. The war of attrition starts to tip in favor of the xenos invaders. The last Steel Fury squadron, the Swords of Ghodba, is crippled by sustained Bio-cannon fire and swiftly overrun by numberless gaunts. Its crew commend their souls to the Emperor, taking up their laspistols and autoguns and preparing for a last stand. Upon throwing open the hatches of their mobile fortresses, the crew of the Swords are stunned to see squad after squad of black-clad Space Marines forming a cordon around their tanks, the relentless pounding of their bolters and the billowing flames of their heavy weapons blasting back the Hormagaunts scuttling around them.
The crew bail out, their saviors maintaining the cordon around them as they fight across three miles of corpse-strewn battleground to reach a squadron of Doomhammers, whose crew had been slain by Lictor attacks. With the assassin-beasts blasted apart by pinpoint volleys from their Legionnaire escort, the crew of the Swords quickly familiarize themselves with the weapon suites of the Doomhammers and rejoin the fight. The introduction of three more super-heavy tanks and almost a hundred Legionnaires tips fate in favor of the Imperium. The invading swarm is shattered, dispersed, and hunted to extinction, forcing the rest of Hive Fleet Moloch to seek its prey elsewhere.