Saint Celestine is the first one on the roster. She is incredibly cheap for what she brings to the table, though she has one massive weakness: Toughness 3 and no Eternal Warrior. That being said, the rest of her stats are brilliant for her very modest points cost of 135pts. She is Jump Infantry, boasts impressive close-combat stats and has a decent save (2+/4++). Her blade strikes at Strength +2 in close combat with the Master Crafted special rule, allowing a single re-roll To Hit, and also functions like a heavy flamer (Strength 5 AP4 Template). She allows her Leadership of 10 to be used for any Act of Faith or War Hymn within 12” of her, which is a nice addition but will largely not be used due to her nature as Jump Infantry; she will probably not be in the middle of your army. If she does bite the dust, however, she will get back up with full wounds on a successful Leadership check, which is almost a guarantee on Leadership 10. Beware: this can only happen once, so be careful!
In my opinion she is best used alongside a unit of Seraphim, a decent unit in itself. If left by herself she will be picked off by a stray plasma gun or lascannon shot, but in a squad of Seraphim the whole unit must be killed off before Celestine herself drops. If played carefully this should not happen as the unit has the Hit and Run special rule. This means that you can move up and unleash flamer death, charge in and fight two rounds of combat, shielding them from your opponent’s fire power in the following turn, before leaving combat on an Initiative test (of 7. So a roll of a 6 will keep you in combat, otherwise you can break off!). This makes for quite a decent hit and run unit for the Adepta Sororitas.
My favourite HQ in the codex! This is largely due to her being the only unnamed HQ in the codex, but even in the glorious days of the Witch Hunters codex in 3rd edition I was using a Canoness and their less experienced counterpart: the Palatine. The Canoness does not have the sort of knock-out stat-line of a Space Marine commander and her Act of Faith is decent, but not great, giving her and her unit Hatred for a turn. However, she will always come in at a modest cost, only costing 95pts if you give her a simple power sword and rosarius and weighing in at early 100s if you decide to go pricey and give her a relic. The only problem is that unlike other armies, a single Canoness can only take a single relic as opposed to being limited to one of each relic, but allowed to take multiples of different relics. Nope, there will be no interesting combos here unfortunately.
Generally I use a Canoness defensively. I’ll sit her in a squad of Celestians or a Sororitas Command Squad (because I’m a fluff player) in the middle of my army acting as whatever sort of melee deterrent that a Sisters army can cough up. As I said, she cannot go toe-to-toe with a lot of HQ units, but she may be able to pick out a sergeant or two if it comes to close combat. Otherwise she is just a cheap and efficient HQ choice, and your only choice for an unnamed HQ. I always take at least one; sometimes I will even take two.
Sororitas Command Squad
If you want to be a fluffy player, you take this squad. If not, you can still benefit from taking this squad. You may take one of these per Canoness in your army, which is fitting, considering that they are a group of bodyguards to a Canoness. It’s basically a squad of Celestians where they can all take heavy or special weapons. I see this squad as having two uses.
Firstly, the more fluffy one. You take a squad, upgrade one to a Dialogus for the laud hailer’s Act of Faith re-roll bubble; take a Hospitaller to give the squad Feel No Pain and general survivability; take a blessed banner, and then stick them in the middle of your army with a Canoness. These ladies are not suited for leading from the front as they drop like flies when sneezed at, due to Toughness 3 and the same 3+ Armour Save as the rest of the army. As a squad of five members, they can easily get focussed down in a turn.
Secondly you could give all of them meltaguns and stick them in a Repressor for a drive-by anti-vehicle squad. Or you can give them all heavy bolters and have them sit with your ranged troops handing out an unhealthy amount of shots every turn. I would just take Dominions or Retributors, personally.
It’s also an excuse to take more Immolators, as they can take one as a Dedicated Transport. I like my cheap vehicles, so this is always a plus for me!
I have very little experience with Jacobus, though he looks like a support character. He accompanies a unit, makes them Fearless, gives the Counter Attack and gives them an extra, free use of their Act of Faith once per game (if he is your Warlord he also increases their Shield of Faith Invulnerable Save to a 5++)
Other than this he is just a normal Priest with better stats. He retains War Hymns but otherwise is very lacklustre in close combat. I can think of a few uses for him, though I would keep him with Repentia if I were feeling lucky as his 5+ Shield of Faith buff combined with his free Act of Faith makes them survivable enough to at least get into close combat. This tactic, however, will give your opponent Slay the Warlord as you’re putting him (he is only your Warlord if you have no Canoness or Saint Celestine as his Leadership is lower at 9) with a unit of Repentia. He could also do well in a unit of Celestians and doesn’t really need to be your Warlord in this configuration as whilst the 5+ Shield of Faith is nice, Celestians wear power armour and will probably be in cover.
Personally, I would avoid Jacobus. I’ve heard people say that he is really good, but I just can’t see it. I would rather spend a lot less points and just get a normal Priest instead.
Ministorum Priests are great when put in a unit like Repentia, Battle Conclaves or Celestians. They give the unit they are in the Fearless and Hatred special rules and one of their War Hymns allows them to re-roll their To Wound dice in close combat, something that Sisters really need at Strength 3. Another allows them to re-roll all failed armour and invulnerable saves, which makes all non-Repentia units rather durable with re-rolls to power armour saves, though the third that allows the Ministorum Priest to use the Smash special rule is rather useless. He is not there to do damage and thus should not be given any upgrades whatsoever, least of all should be Ecclesiarchy Relics, and should never accept challenges, he should hide behind his unit and inspire them with his War Hymns. You may take up to 5 in one detachment and they do not take up an HQ slot. Take one per close combat squad you have in your army as he is cheap and offers some really handy buffs in assault. His War Hymns, however, are not too reliable, requiring a Leadership check on his rather paltry Leadership of 7 that do not gain re-rolls from a Laud Hailer. They are, however, capable of being used more than once. Just cross your fingers and hope that something does not get stuck in his throat when you need his oratory the most.
However, due to their points cost, there is no real reason not to take five of them. Fearless and Hatred and the occasional War Hymn is definitely worth the 25pts investment, doubly so for your melee combat units. Five will cost you 125pts, but will provide your army with some real staying power.
Ecclesiarchal Battle Conclave
Following up from the Ministorum Priest is the Battle Conclave, a unit that can be taken once per Ministorum Priest and does not use up a slot on the Force Organisation Chart. A great unit to accompany a Ministorum Priest into battle, though rather pricey when considering all the upgrades that they require to really be good. There are only two real ways to take this group. Crusaders at the front for potentially re-rolling 3+ invulnerable saves due to storm shields and the Ministorum Priest’s rantings and the rest as Death Cult Assassins to hand out the pain to MEQs or Arco-flagellants to kick hordes about with a storm of attacks at Strength 5. Depending on what you need beaten up in close combat, a Ministorum Priest in a Battle Conclave will kill whatever gets into combat with it with the exception of units like Genestealers. A very painful combination, but rather pricey, although a 200 point close combat death squad is definitely worth taking, at least for counter-assault tactics. Beware though, they are all Toughness 3 with generally bad saves, barring the Crusaders’ 3+ invulnerable, so large amounts of boltgun or lasgun fire will whittle them down quickly. They can also take a Rhino or Immolator as a Dedicated Transport. In my opinion, it is generally always a good idea to take a Rhino as they are so cheap and provide some mobile line of sight blocking at the very least.
Having seen these in play, I can whole-heartedly recommend them as a counter-initiation unit in your army. The Crusaders soak up the firepower on their 3++ Invulnerable Saves and the Death Cult Assassins or Arco-flagellants murder everything in their path. A really great unit to take if you want to add some Ecclesiarchal close combat punch into your list and arguably the best melee combat unit in the whole book.