Alright, time to review the assassins! First off, they are an army of the Imperium and have all the same ally rules that those follow (BBs, Allies of Convenience, etc). The dataslate can be used in two ways, either you can take one assassin as an ally, or you can take the assassinorum execution force formation, which consists of one of each assassin. Either case, there is the operation assassinate special rule, which in a game where you are playing victory points, you get an additional victory point if your opponents warlord is removed as a casualty as a result of wound/s caused by an assassin. The execution force also has preferred enemy (warlord), which is a decent little boost. I like it, its fluffy and useful and steers you toward using them in actually trying to assassinate a target, but is in no way over powered. Its just enough to help you out, but only helps if you really use them while headhunting.
All assassins have the same stat line, WS BS 8, S T 4, 3 Wds, I 7, 4 A, Ld 10. Now I'm not hugely familiar with their stats from the old GK book, but I believe the only major change is that they got an additional wound, feel free to comment if their are other stat changes. From a stat perspective, they are pretty damn good, T 4 does mean they can be insta gibbed by S8+ weapons, but overall they are very solid.
First assassin in the chute is the Vindicare, he is the most expensive at 150. He has blind grenades and a ccw. He has the trademark Exitus pistol and rifle. The rifle is 72" range, S X AP2, heavy 1 sniper with exitus ammo. The pistol is the same profile, but with a 12" range. Exitus ammo is as follows, the shield breaker round ignores invul saves (wounds, glances, pens), the Turbo penetrator counts as S 10 vs vehicles, and causes D3 wounds against other targets, which is ok, the hell fire round always wounds on a 2+. Then comes all the special rules. He has fearless, infiltrate, move through cover, and stealth. Then there is deadeye shot, which makes all his hits precision hits, independent operative means that a character IC or otherwise can never join him, lightning reflexes gives him a 4+ invul, no escape gives a -2 to look out sir rolls for characters and ICs, and his spy mask gives him ignores cover. Important to note that deadeye and spy mask do not work for snap shots. Deadeye and no escape means you have a very good chance of killing character, and a 50/50 of keeping the wound on ICs, so much better than normal which fits their role.
Overall I like him a lot and at 150 I think he is about right. When it comes to shooting, he is def more reliable vs vehicles with the turbo penetrator, but even while D3 sounds good on non vehicles, you still need a 4+ to wound. The shield breaker is very nice for models or units that have a really good invul save, but it suffer from needing a 4+ to wound as well, as sniper rifles are not that great in the far future. The Hellfire is the most reliable vs infantry and as long as they don't have a good invul save, this is the one I would use. If you can get buffs on him through area warlord traits and phsychic powers, then the other shots become much better. Rerolling to wound is really what you are wanting on him, to up his chances of wounding with the other shots. Turbo penetrator is great against vehicles, especially light one, but against multi wound units, its too reliant on getting that 4+ on one shot, without some buffing, its a crap shoot. The nice thing is that he always ignores cover and is always AP2, so wounds are going through. His best use is killing Sgts, as they will need a 6 to look out sir, and the hell fire round will take care of just about any Sgt equivalent. Against opened topped vehicles he is also quite good, with a solid chance of blowing them up and a good chance of destroying a weapon or immobilizing it. With buffs he can also take down multi wound models, but without your playing the chance game, it can work but 50/50 is not enough to count on.
Having infiltrate and stealth means that finding a nice ruin to shoot from is really important. Another good way to use him is to bring a bunker, give it good fire lanes, and throw him inside it to protect him. He can jump up top if he needs to, but if you place it right he will be able to hit a lot of targets. He is a great all rounder that can threaten just about anything, my only gripe being of the sniper mechanics in 40k.
The next assassin up is the Callidus, which is 5pts cheaper than the vindicare. Same stat line, and a lot of the same special rules. She has Fearless, fleet, infiltrate, hit & run, move through cover, and precision strikes (normal one, 6s to hit), as well as independent operative, no escape, and lightning reflexes. Unique special rules are polymorphine which means she can set up like marbo of old, allowing her to infiltrate up to an inch from an opponents model. If place in reserve, she can choose to come on from the opponents board edge. In either case, the first turn on the board, only snap shots can be fire at her, which is nice meaning no blasts or templates can target her. In addition she has reign of confusion which allows you to reroll seize, and your opponents first reserve roll is -3, which are not bad buffs at all. Wargear wise, she has 4+ invul (technically special rule), a neural shredder which is S1 Ap2 template that wounds on a 4+ but cannot hurt vehicles or buildings. A phasing sword which is S user and AP2 and has phasing hits which on a 6 to wound ignores invul saves. Poison blades are S user with no AP but are poisoned 3+ and rending. Both are normal melee weapons, which giver her an extra attack.
I actually don't mind her and think she has some nice uses. Being only able to be targeted by snap shots is very nice and she gets this bonus if she does not infiltrate as well, so you can just deploy her normally and still only have snap shots target her. The reroll to seize is a nice minor bonus but the -3 to reserves for the first one is really nice. A smart opponent with multiple reserves though will get around this by rolling for an expendable unit first to get through this and then the important reserve rolls after that. The pistol she has is decent, being a template meaning you can get a good number of targets under it to make up for needing a 4+ to wound, and being ap 2 means they are going to die. She has 6 attacks on the charge and at I 7 she is going to be hitting first in most cases. Against anything T4 and below I would use the sword, and the poison blades on anything tougher than that. She could be good in a challenge, depending on what she is fighting, able to land a good number of hits before she can be struck back.
Overall the callidus is a neat little assassin, not as straightforward as most but has some nice uses as a disruption unit and just plain messing with your opponents plans. Hit and run is great to escape combat that she probably can't win, in either case she only has a 4+ invul so weight of attacks will bring her down, and beware any S8.
The Eversor is next and is the cheapest at 135. Same stat line. He has fearless, feel no pain, infiltrate, move through cover, and furious charge. He has independent operative, no escape, and lightning reflexes. He has fast shot, which allows him to fire four shots with his pistol at the same target and can be any mix of ammo (bolt pistol, needle pistol). He has bio meltdown, which when he losses his last wound, all models within D6 inches suffer a S5 AP - hit. Frenzon allows him to assault 3D6, and gets 3 additional attacks on the charge instead of one. Sentinel array allows him to fire over watch at full BS. He has a power sword and melta bombs, the executioner pistol is a bolt and needle pistol, with the needle being poisoned 4+ with no AP. The neural gauntlet is S user with flesh bane and shred.
On the charge he has 8 attacks (4 base, +1 for pistol and weapon, +3 w/frenzon) at S5. He is really good at carving through units and would be great in overloading a character with wounds in a challenge. He is really straight forward, find a unit you want to kill and charge him into it. With a 3D6 charge, he can reliably get into combat and even pull off some long charges. He really isn't going to last long, but that's ok, he is bomb as well, so get him stuck in and when he dies, he takes more with him.
The last is the cullexes, the psyker killer, and he is a beast. Same stats and has fear, fearless, infiltrate, move through cover, preferred enemy psykers, independent operative, lightning reflexes and no escape. Life drain means no armor saves can be taken against wounds inflicted in CC, and any to wound of 6 causes instant death. If it is a psyker, all its cc attacks have instant death. Psychic abomination gives all psykers within 12"(friend or foe) -3 leadership, they do not generate warp dice into the pool and only harness warp charges on a 6. Cullexes can never be targeted by psychic attacks or powers, though units around him will still be affected normally. Any blessings or maledictions affecting a unit within 12" immediately cease. So this guy can cancel anything, good bye invis. His Animus Speculum is a ranged weapon that is fired in the psychic phase and allows him to still run or shoot in the shooting phase. It is R 18" S 5 AP1 and has absorbed warp charge to determine the shots. Total up the number of Mastery Levels within 12" of the psyker, you can add three more by removing them from your warp charge pool. Etherium means that all attacks against him are WS and BS 1. He has Psyk out grenades which he can throw which causes a psyker hit by it to suffer a perils of the warp. Pskers do not gain a bonus attack for charging the cullexes, unless he is locked in combat from a previous turn or gone to ground.
This guy is just plain nasty against psykers and his ability to nullify blessings and maledictions automatically is just plain awesome. He is really an awesome guy to take if you are facing psykers. Get him close and let him go to town on them. He is ok in assault, but only is S4 so he won't do much to high T targets, but will murder a lot of T4 and less psykers. If you can get him close to a lot of psykers, he will just murder them. If you are facing demon spam, he is money, just plunk him down and deny all those warp charges and let him rip with the Animus. He is most likely going to be a throw away guy, as there is no way to hide him in a unit, like the rest of the assassins, and needs to get close to use his abilities. He will be a target, so take that into account and get the use out of him early.
Overall I think the assassins are great and there is a lot of ways to use them. For my Tempestus, they are great and the execution force adds a lot to them with long range shooting, callidus buggery, eversor meat grinding, and anti psyker. If you are facing certain threats in your area, you can pick one that best deals with that issue. I really like them and will definitely be playing with them in the future.
GG