Disclaimer: I don't own Fallout or Kuroinu: Kedakaki Seijo wa Hakudaku ni Somaru.
A column army of Vaulters, Dark Elves, Darkspear Trolls, and Frostwolf Orcs were marching along with 12 Anaconda Tanks, 18 Humvees, 7 Autocannon Tanks, 10 M113 APCs, 5 Juggernauts, and mounts from horses, hellhorses, wolves, bears, and raptors. They're heading to Castle Mandeville, stronghold of Sir John Mandeville and internment camps were prisons built to contain the slaves from different humans and demi-humans captured by the Black Dog mercenaries and Mandeville's slavers.
As they marching through the rock valley, up on the cliff they were observed by Black Dog Commander Aedelas Blackmoore and his lieutenant Tammis Foxton beside them are the catapults that are prepared to be fired. Down on the cliff as the Black Dog mercenaries, Pig Orcs, and Red Goblin Imps were hiding behind the boulders with their weapons prepared.
Blackmoore holding his telescope as observes the approaching army until he gave the order. "FIRE!"
The trebuchet groups were already at work, reeling back the great long arms of each device, hoisting up each of the massive swinging buckets, each holding some seven tons of sand and stone. When all five arms were pulled back into the loading position, the stones were loaded into the leather slings.
"LOOSE!" Black Dog officer shouted. At his command, all five of the arms were released, the massive counterweights began to fall, and five massive stones were slung at great speed through the air towards the column. It heading straight on the soldiers and the tanks, but it only hits the side of the rocks as the Vaulters and their allies noticing then the Vaulter officer on the top of the cliff.
"Come on!" The troops running advance towards their objective, the cavalry got first as the hidden mercenaries showed up as they shooting crossbows to the cavalry units and they charge towards them. Behind the column were 10 M939 trucks carrying OTO Melara Mod 56 howitzers were now position as they pointing their targets as the howitzer officer. "Fire!"
The howitzers firing onto the mercenaries and the top as the catapults blown up including Blackmoore and Tammis. The Black Dog officer sees that Blackmoore was down on the debris as he gave the order in frantic. "Sound the retreat! Retreat to Castle Mandeville! Retreat! Retreat!" The Black Dogs were fleeing from the battle as the Vaulters chasing them with warcry.
"After them, don't let them get away!" The Dark Elf woman named Chloe, Olga's attendant order the troops pursues the Black Dogs.
Author's Note: I'll update the next chapter.