[You lash the burning Imperial banner to the back of your power backpack. Wing panels along your vibranium armor shift and lock into propulsion mode.]
[You take your place at the front of the crowd, the Blood Scythe in one hand, wreathed in green light, Forgebreaker in the other, lightning threading along its head.]
[You lead your assembled Astartes and mortal warriors in a fast march toward the mouth of the cave.]
[Then you reach the surface, and the artillery fire waiting for you is already deafening.]
[The scale of the battlefield stops you cold for half a second. Even with everything you have seen, this is more.]
[The plain stretches to the horizon in every direction, and every inch of it is fighting.]
[Cultists and rebels swarm the ground in their thousands, daemons of the four Chaos Gods moving among them.]
[Chaos Astartes of the Black Legion push forward in combat squads, shielding Chaos tanks and daemon engines as they cut through the surging lines.]
[Farther out, the Mechanicus's God-Machines stand with the agile Taranis Knights at their feet, straining under a relentless Chaos barrage. Void shields flicker across Warlord-class Titans and Knight armor alike. It does not look like a battle either side is close to winning.]
[Overhead, through the smoke, Cadian Marauders fall one after another, shot down by Chaos war engines or caught in walls of rising flak.]
[The aircrews do not break off. Out of ammunition, they ram their gunships straight into the enemy, lascannons and heavy bombs spent first, the aircraft itself spent last.]
[Inside the skull helm, you take a slow breath.]
[You raise a vibranium hand and grip the Blood Scythe tighter.]
[Thirty Leman Russ tanks and five Land Raiders appear out of nowhere around your gathered force, treads slamming into the earth hard enough to dig themselves in.]
[Inquisitor Greyfax reacts fast.]
[Bolt pistol in hand, she pulls her Stormtroopers, the ones best suited to driving, straight into the vehicles.]
[Engines roar to life. Cannons deep in the hulls start their barrage.]
[The burning banner at your back draws attention fast, Chaos daemons and Chaos Astartes among the enemy ranks alike. After one beat of hesitation, they come straight for you.]
[Boom. Boom. Boom.]
[Cyclone missiles and storm bombs from the Ultramarines company slam into the advancing Iron Warriors, shields raised, and tear their line apart.]
[Beside you, a dozen Salamanders hold their ground, flamers burning a wall through the daemons pressing closest.]
[Greyfax's voice cuts across the noise, sharp and commanding.]
[Leman Russ and Land Raiders roll forward with a shared, thunderous growl, laying down cover fire for the bulk of the Eagle Legion, lascannon fire chewing into the endless enemy line.]
[You turn your head. The Custodian is already beside you, guardian spear in hand.]
[You give him one hard nod.]
[Both of you move at once, power armor answering in perfect time, and charge straight into the Iron Warriors and the daemons pressing behind them.]
[Boom!]
[The Blood Scythe sweeps forward with everything you have, and the dense press of daemons and cultists ahead of you comes apart into flying fragments of flesh and blood.]
[Your other hand brings Forgebreaker down. A storm shield shatters under the blow, and the Iron Warrior behind it goes down with it, driven into the ground.]
[Beside you, the Custodian moves like something faster than his size should allow, guardian spear finding gaps in ceramite and plate with every pass, keeping every Chaos Astartes that comes near from ever reaching your back.]
[You send the Ten Rings up and out in a spiraling storm of metal, grinding through the daemons pressing in around you.]
[Maybe it is the wind. Maybe it is some small mercy of the Imperium looking out for you. The burning banner at your back throws off threads of gold flame now too, and they catch on daemon after daemon as they pass.]
[Then your ears catch it. A furious roar, distinct from everything else. Khorne's army.]
[You turn the skull helm, already slick with blood, toward the sound.]
[Kilometers off, a warband of Chaos Astartes wearing the mark of the Bloodhand comes on through a mass of cultists, screaming "traitor" as they charge.]
[You take a breath.]
[You loose the Psychic Ray from the Mind Stone atop your helm, one long continuous burst aimed straight at them.]
[The beam cuts across a wide stretch of the battlefield, and dozens of Chaos Astartes go down where it passes, cut through the waist or the chest, chainswords still in hand.]
[For a moment you think you have bought yourself some room.]
[Then every daemon on that plain, every one belonging to any of the four Chaos Gods, seems to receive the same order at once.]
[Some of them abandon fights they were already losing, break off mid-engagement, and start converging on you.]
[But it is not only the enemy that has noticed you are here.]
[Astartes and mortal companies across the Imperium's line have seen the reinforcements arrive. The Iron Wolves Company and the Bloodhowl Company of the Space Wolves, the Black Templars under Marshal Amalrich, all locked in their own brutal fights, seem to feel it too. Heads come up. Voices roar. Whatever fight they had left in them a moment ago, it is more now. What is left of their strength gathers, and surrounded on every side by Chaos troops, they keep pushing toward you.]