Hive Fleet Magnus Vectus seems to bear a special kind of hatred for those it has not yet eaten. Here we have documented everything we know about them.

Tactics- Magnus Vectus uses a wide array of tactics, but is most infamous among those who have fought and lived to tell about it for having more winged creatures than normal, and for making greature use of 'Toxin Sacs' and 'Adrenal Glands' than most other Tyranids we have encountered. We are constantly surprised as normally weak creatures damage, overwhelm and destroy our toughest creations, and it is reccomended when fighting them to never understimate the damaging potential of even the smallest in their ranks. Further advice can be given in that their speed should be taken even more seriously. Creatures scramble desperatly, using all six limbs to drag themselves into position, and worse yet, some will leap great distances to bear down on the foes.

Xenology- Magnus Vectus' signature trait is their blood. Within the blood of these Tyranids is their real weapon. When prompted by the Hive Mind, or when the creature become excited, massive amount of adrenaline are pumped by their larger than normal hearts into their bloodstream. Specimens have been found with as high as 15% concentration of adrenaline, more than enough to kill man, a Space Marine, or even other Tyranids. This adrenaline activates the powerfull acids and poisons held in it's blood, and they begin to seep out of it's pores immediatly. The adrenaline and the pain drive the creature into a frenzy, it's eyes glaze over with tortured desperation, and it charges into battle with an inhuman screech, the very image of chaos and misery. The adrenaline, and even the pain itself, give the monsters a hightened sense of awareness in combat, and greatly increase the speed at wich it reaches combat. While a well trained space marine can effortlessly cut through swathes of normal Gaunts, he will find that these ones death coated talons will prove more effective, and that the creatures blood frenzy will make it a more skillfull opponent than even he. Even more feared are the great Carnifex Magnus Vectus, whos bloodcurdling roar of anger, frustration, and pain, will strike fear into the heart of any lesser creature. They have been found with an adrenaline concentration as high as 40%, barely leaving room for their various toxins and phage cells. Although no stronger than other carnifex, the hightened senses of these will make it an impossible opponent in combat, not only are they fast as they are skilled, but huge chimeneys on their backs spew miasmic clouds, causing instant sickness to all those around them. All Magnus Vectus have greatly enlarged hearts, wich pump at such a rapid rate as to sound more like a low hum than a beat. When fighting, constant hyper ventilation is common among them, as are sudden bursts of even greater speed as the creature screams horribly. No flesh, no muscle, no sinew could ever take this kind of strain for extended amounts of time, and twords the end of an engagement, many Tyranids will be seen with limbs hanging uselessly after over-exerting their own tendons, gums and palms bleeding from being clenched so hard, hooves digging into the ground littered with the deadly blood from their many wounds. In longer engagements, many can be seen simply dropping to the floor, their vitality spent, without enough energy in their body to keep their heart beating. In some cases the monster's acid will be more powerfull than it's flesh, and small holes will form on the things tortured body, dripping with it's venomous fluids. Bleeding from the eyes, ears, mouth, and just general bleeding is always preseant among them. It is reccomended that Imperial Gaurd regiments be sent to combat these monsters, as if they are compromised there is less trouble than with the other forces of man. In the name of the God Emperor, these foul xenos must be dealt with somehow.

Quotes-

"The thing that amazed me most was the way those things moved. Now, I've always been proud of my swordsmanship, least before damned bugger took my arm. More proud than my aim at least. But that thing was all over me, and there was nothing I could do." -Major Berringham of the Imperial Guard

"I am the very best that man has to offer in the way of the sword, and I am very proud of that. When that damned Carnifex creature bore down upon me, I stabbed it in the chest. Must have been six feet of sword in that thing. I was proud for a moment, but when I saw it's eyes, God Emporer those eyes, I knew that it hadn't felt a thing, that it knew it was already dead, and that the last thing it wanted was to bring me and everything else it could with it. Do you know what that's like, fighting an opponent who knows he's already dead, who no matter how badly you hurt, is already wounded more greviously? That is Magnus Vectus. I will not fear again untill once more I cross it's path." -Goodrick 'Blademane', current Emporer's Champion of the Dark Templar.