"Hive Fleet Vicarius is a splinter fleet of hive fleet Leviathan, and is attacking ‘up’ the galactic plane. Although it is relatively small in size, its creatures seem to be highly evolved, able to take out anything twice their size.
They have already taken two worlds: Karmanas, a bitter cold ice planet, and the other, Amabonius, a jungle and desert planet, teeming with life, defended by a Tau expeditionary force.
There are reports that they have engaged the orks of the Overfiend of Octarius, and have also destroyed a raiding force of the Eldar Craftworld Iyanden that landed on Karmanas seeking to try and halt the splinter fleet.
They seem to be thriving on the ork life, as is shown by the new, tougher genestealers, stronger and faster warriors and Scythegaunts, and have developed a new breed of hive tyrant, that can lay down a withering hail of fire to tanks, infantry and monsters alike.
On a frozen ice planet, the tyranid clashed with the metal warriors, the necron, and were defeated. But now a new, improved force has amassed, aiming for Tarphonis Alpha, a lush snow world, with magnificent ruins and great forests of Gekal trees, which can survive under the harsh conditions. This force has so far destroyed a Slaneeshi terminater company, and an army of Slaneeshi noise marines, who had landed on one of Tarphonis Alpha's moons. A fierce battle is raging on Tarphonis Alpha against the Space Wolves and Imperial Guard, but already Hive Fleet Vicarius is turning towards some new targets; anyone that stands in their way.
The splinter fleet has evolved to be extremely camouflaged in the snow and ice, being shades of grey and blue, as these are the types of worlds and terrain that the fleet has encountered most enemies on thus far. The fleet also prefers this type of terrain, as the conditions give great disadvantages to their enemies, while not hindering the Hive Mind in any way. They creatures also have brilliant yellow markings over their grey carapace, which works like the zebra effect, effectively blinding the enemy as they struggle to distinguish between seperate targets in the brilliant swirl of colours.
There seems to be a concentration of all types of races fighting each other, near the Eastern edge of Ultima Segmentum, and the tyranid look greedily upon them, and have already begun to engage another fleet of Tau, while the Eldar, joined by some of the mysterious Harlequin, seek to halt the Fleet. It looks like a big struggle for Splinter Fleet Vicarius, but the Hive Mind always requires food, no matter what..."