Bloodcrushers of Khorne
In the list of Khorne units that really personify what the Blood God is all about, those that are mounted on a Juggernaut come in a very close second in terms of the sheer amount of violence they can do. First things first though, they have a pretty good stat line with a WS, BS and S value of 5, T and I of 4, Ld 7 and W and A of 3. They are also a Cavalry unit which means that they move 12" in the movement phase, aren't slowed down by Difficult Terrain (but still test for Dangerous Terrain), can fall back 3D6" (though I'm not 100% sure if Daemons ever can fall back, maybe someone could comment and let me know?) and have the Fleet and Hammer of Wrath special rules, as well as the Daemon of Khorne rule which grants Furious Charge. Fleet allows for the re-rolling of one or more dice for a Charge or Run and Furious Charge grants +1 Strength when the unit charges but the most interesting extra rule for the Bloodcrushers is that they have Hammer of Wrath attacks which makes them unique amongst the Elite choices. This grants the Bloodcrushers an attack (on top of the extra one for making the charge) that automatically hits, is resolved at Initiative step 10 with the Strength of the unit and no AP value. The Bloodcrushers already gain an extra attack whenever they charge and go up to a Strength value of 6 but with Hammer of Wrath they gain another attack per model which gives a basic 3 Crusher unit 15 s6 attacks and for each additional model added to the unit they gain another 5 s6 attacks.
The Bloodcrushers have the exact same unit upgrades and equipment as the Bloodletters. I'm guessing this is due to the fact that they're simply Bloodletters on big metal rhinos so it's actually the Bloodletters carrying the equipment and not the Juggernauts they ride. They can take the Icon which, as with the Bloodletters, costs 10 points and carries with it all the benefits of any other Icon but with the speed boost of a Cavalry unit. Also like the Bloodletters, the Bloodcrushers can upgrade their Icon to the Banner of Blood for 10 points. They can also have an Instrument for another 10 points as well as a unit champion, the Bloodhunter for 5 points. The Bloodhunter grants an extra attack so with all the special rules in place he gains 6 s6 attacks at AP 3 (with the Hellblade). To cause a wound we're looking at 2+ up until T5 which is 3+, then at T6 it's 4+, T7 is 5+, T8 is 6+ and above there they can't cause a wound at all. Considering that there isn't much that goes above T4 and even less above T5 there won't be much cause for concern when it comes to wounding. At WS 5 there isn't much worry about not hitting things either so you'll get plenty of hits and plenty of wounds and unless you're talking Terminators then you're going to get a lot of kills too. As with the Bloodreaper (and in fact all other Unit Champions of this army) they can take Daemonic Rewards and up to 20 points of them. They can guarantee the same 4 weapons that the Bloodreaper can take (Etherblade, Greater Etherblade, Axe of Khorne and Blade of Blood) but again it must be considered whether the points are so wisely spent here or whether they can be better spent elsewhere.
You may be reading all of this and wondering where the downside to such an awesome and powerful unit is, well I'll tell you. The downside to the Bloodcrushers is their expense; we're looking at 135 for a basic unit of 3 and each additional Bloodcrusher is 45 points which makes them the second most expensive Elites choice (Beasts of Nurgle work out as most expensive for a full unit) but also lacking in survivability. They are pretty tough but once an attack gets through then all they have for protection is a 6+/5++ saving throw which isn't great in all honesty. Of course from a strategic point of view what you want is to throw them into the enemy as fast as possible, kill as many as possible and not get attacked in return. Basically the same strategy as the Bloodletters but with more speed and a lot more attacks. With the Icon and the Instrument added in then the Bloodcrushers are able to speed across the battlefield, drop in a couple of units and dash off to cause more mayhem. My advice, as with most of the units in this army, is to use their speed to go from cover to cover (bear in mind that with Run moves they are able to potentially move 24" in one turn but cannot charge) until they are close to charge range, all the while bringing in more and more of the army. As soon as they can charge, have them do so into the first unit that they can and rain down utter hell. Now with their cost and their slightly fragile nature they probably aren't suitable for smaller armies but as the points allowance goes up so too does the viability of a unit of Bloodcrushers and as the points go higher and higher it becomes possible to make the unit bigger or even to have multiple units when the point is reached that the FOC is doubled. As the Blood God would prefer, strategy with His units is basic; run, smash, kill. Lather, rinse, repeat as necessary.