Azrael
He's a bit of an enigma really. At first you think he's awesome because you can take both Deathwing and Ravenwing as troops for about half the number of points it'd cost to include Sammael and Belial for the same result. Then you start to write a list and realise that he doesn't play well with others in that he can't join either DW or RW. This means you need to spend points on a squad for him. Sure you can stick him in a tactical squad for cheapest but that's somewhat wasting his abilities. Anyway, I'll get back to that. For now let's look at what he offers.
Stats-wise he's pretty solid. Fairly standard chapter master stuff but with 2+ armour and a 6+ FNP which is about 86% chance of saving a normal shot.The real fun comes from his special rules and chapter relics though. He gives your entire army Ld 10 which not only saves you a lot of veteran sergeants but with Stubborn for most of the army (that isn't already Fearless) you aren't going to be failing many Morale Checks. You get to choose his Warlord Trait which is a nice touch but realistically you only want For The Lion or maybe Brilliant Planning.
His weaponry is pretty decent with a Master-crafted combi-plasma that causes Blind (more on that in a minute) and a +2S Master-crafted power sword. The thing that gets most people excited is his 4++ save for him and his unit. This combination goes some way to helping with his foot-slogging issues. Personally I think the best way to use him is with an assault squad in their freebie drop pod. If you're feeling flush (points-wise) then by all means make it a veteran squad but either way you want him in the thick of it to make the most of Furious Charge (from For The Lion).
Trouble is, I just can't get excited about Azrael. It's annoying that you have to buy a squad for him to get the most out of him. This pretty much ruins the feel of your army which otherwise only contains terminators and bikes. Before you know it you've spent 500pts on him and his squad which doesn't leave you much left for the rest of the army. Ultimately I think people will be using him with allies and probably in the form of Imperial Guard. Either way I'll struggle to find a place for him in my armies.
It's worth noting that he hasn't really changed from the old codex even if he is 10pts cheaper!
Ezekiel
Whilst he still has the same problems as Azrael in that he needs a squad to tag along with, Ezekiel is just ridiculous for his points. He's disgustingly cheap for what you get and cheaper than he used to be! A regular librarian with Mastery 2 and terminator armour is 130pts. For another 15pts you can have Ezekiel who's Mastery 3!
Let's go through all the stuff you get for just 145pts. Let's see he's a librarian with 3 wounds, BS5 (for those Witchfire powers), 3 attacks base and initiative 5. For his stat line alone I'd pay 145pts but there's more. He gets Mind Worm which if you get lucky with the focused witchfire could seriously gimp an opposing character if it doesn't kill them!! He gives all units within 6" a +1 bonus to WS. He's also got a Master-crafted force weapon which, although two-handed still gets 4 attacks thanks to his better stats. Personally I think that little lot is a bargain!
I'm determined to find a way to get him into my army just to give Mind Worm a go. It's a bit of a shame there weren't proper Dark Angels psychic powers but nevermind. I'd probably go with Telepathy for his other powers as he can fire off those ML2 powers and still get a Mind Worm. I reckon sticking him in a drop pod could be brutal if him and his squad can survive the initial fusillade of fire.
As a bonus the DV librarian makes for a perfect representation of Ezekiel (you can just stick a banner on him) which saves your precious pennies.
Asmodai
From the sublime to the ridiculous. Asmodai feels really badly thought out. When you compare Ezekiel to a standard Librarian there's no contest. If you can fit him into your army plan you ought to take him. Asmodai on the other hand isn't much better than a normal Interrogator Chaplain. He has an identical statline for a start. You pay an additional 30pts and don't get a whole lot in return.
Maybe I'm missing something but you lose an attack (as he only has one specialist weapon) and are forced to take The Hunt where a normal Interrogator could take a roll and maybe get something better. The only "bonuses" are that he causes Fear (which GW seems to think is much better than it actually is) and his weapon causes Instant Death. Well it would if your opponent doesn't pass his armour save as it's AP-.
The less said about him the better to be honest. Save your points.
Belial
Back to the good stuff then. Belial is obviously the character of choice if you want to field a full Deathwing army (more on that soon). He got a bit pricier in this edition of the codex but he's got a bit more meat to him than he had before. In addition to the stuff he always had he's got a few nice toys.
For starters he's now WS6 (not a massive deal but still) and his sword is nicer. It's still a master-crafter power sword but it's now got Fleshbane which means he wounds on 2+. He's got 5+ precision shots but since he's just got a storm bolter it's hardly devastating.
The big thing here is that he's the first character in this list that plays to the DA army of terminators and bikers. The key thing is that his squad won't scatter when they arrive. I'm planning to make him out of terminator bits rather than buying the model but even so I'm determined to write him into a list.
It's a bit of shame that he doesn't give a few more bonuses to his terminator brethren but the not scattering thing could really come in handy. For the points I think he's a reasonable choice and certainly doesn't feel like a tax to unlock DW. The options are still there for swapping out his weapons but I don't know why you would anymore.
Sammael
First off no-one is ever going to take the land speeder. Seriously why would you? Waste a character for the sake of an AV14 2HP speeder. Forget it.
That aside, Sammael is pretty solid. Very similar statline to the other characters but you're also getting T5 of course. Weirdly as the toughest character he's also the only one to get Eternal Warrior. You'd have thought Azrael would have it but whatever. In my opinion he's a little pricey for what he is and I think that's purely down to his EW. Nice to have a plasma cannon in there but there isn't much else to get excited about. He's got an AP2 power weapon which is better than his special character colleagues but he just doesn't excite me to be honest.
Perhaps I've not been making the most of him as I've been using him with a command squad. This gives the squad more survivability with Skilled Rider's +1 to cover and his ability to soak up some wounds but really I think he needs to be with a big squad of Black Knights who are tearing around the place making a mess of things will at those plasma shots and rending attacks.
Let's face it. He's going to see A LOT of use for the pure fact that he unlocks RW as troops. Don't get me wrong he's by now means a bad choice but there's just something not quite right there. Perhaps he should just have a 2+ save or something.
Conclusion
There aren't really any stand-out characters (maybe Ezekiel) but with the exception of Asmodai it isn't difficult to see why you'd take them. In some ways it's a shame that you almost have to take them but personally I probably would've done anyway.
I didn't really intend this article to come across so negative on them. Don't get me wrong I'm happy with them on the whole. I think they just needed to be a bit more powerful for their points. Sure they're not awful but none of them feels like Draigo, Logan or Abaddon. Maybe with time one will stand out though. What do you guys think?
Incidentally, if you're looking for inspiration for converting your characters using the normal kits. Take a look at my mate Jamie's blog where he's done conversion for Belial, Azrael and Ezekiel.