I'm going to devote at least two posts to the Kraken; first off I'm going to evaluate it on its own here and see what it can do, and scratch the surface of what it can do with some casters. After some practice and/or more thinking, I'll start discussing it in the context of an actual list.
Kraken Basics
First off, it's a colossal. (Yarrgh! I be Captain Obvious!) This has a few implications. First off, you deploy this thing first off; it MUST be pre-deployed. Second, the enemy can't control or disrupt it, or move it. The only time it's going anywhere is during its activation. Also, pathfinder. Which is fun.
Third, it's bloody big and durable and hard to hide. Like battle engines, it's never gonna hide behind anything or get ANY defensive buffs, and being in melee is no refuge from combined ranged attacks. It's also got 54 boxes on ARM19, so it can absorb some abuse.
Kraken on the Offense
Shooting
This thing brings a pair of guns - the Hellblaster and the Flayer. Both guns can fire through the entire front arc. They're tied to an average RAT5, and the Flayer is spec'ed out as an anti-infantry gun whereas the Hellblaster is a sizeable high-powered blast weapon. The Flayer's good for d3+1 POW12s out to 12 inches, and Rapid Fire means it can spray those from one end to the other of its range. The Hellblaster is a POW14, RNG16 AOE4 gun that can go up to POW17 with a full load of corpse tokens (and due to the wording of Doom Driver, the blast damage can get up to an effective POW10).
Also of note is the new rule 'Killshot', which allows you to make a single ranged attack ignoring ROF if you take out something in melee. Note that colossals can make their ranged attacks while in melee.
Melee
This thing starts with a pair of PS18 'Harvesters', which are Chain Weapons with Chain Strike on 'em, so you can reach out and punch enemies out to 4" away. With SPD5, you have a base charge range of 12", and you end up 4" away from the target without engaging it at the end of your activation (at least, in theory and in a vacuum).
This model has Collector and Meat-Fueled, which are some of its 'flavor' rules. If it KO's a living model in melee, corpse token. +1STR for corpse tokens, to a max of 3. ALSO, you can remove corpse tokens to give it focus at a cost of one per focus. It lets you trade off hitting power for self-sufficiency.
Also, note colossals have a few extra power attacks, like the no-move slam and perhaps more amusingly, the 'sweep', which tags everything in 2" of one melee weapon. Hilarity can ensue, as a good sweep will KO infantry, help with meat-fueled, AND activate killshot.
What Would the Kraken Like?
I can think offhand of two things the Kraken would like:
1) help hitting
2) help not dying
As we're Cryx, we have access to DEF debuffs. The 'not dying' is very often up to the player to provide by not doing dumb stuff, and also by bringing Necrotechs for repair. There's nothing quite as obnoxious as the enemy dog-piling the thing and failing to kill it, only for a pair of necrotechs to bring it back up turn after turn.
What Casters Can Offer What Benefits?
Asphyxious1
ARM debuff, damage buff...not bad, but a to-hit buff would be nice.
Asphyxious2
Much the same as Gaspy1, but with more desire for infantry. 'eh'.
Asphyxious3
Hey, we have a to-hit buff and a damage buff. This guy could make it work.
pDeneghra
Debuff queen to the rescue. Also, a good feat turn with Scourge and parasite? Yeah, the Kraken can basically auto-hit with 2-4 POW12s and a POW14+, while the enemy's at -5 ARM. That will probably do the trick.
eDeneghra
You have a DEF and/or ARM debuff, and a feat for more DEF debuff/positioning fun. Sadly, Pursuit doesn't work on the Colossal.
pGoreshade
You have a DEF debuff against the living via the Deathwalker, and you can grant it Dark Shroud via Shadowmancer. Sadly, Soul Gate is unlikely to be much use hwere, and you probably won't cast Mage Blight either.
eGoreshade
You get an ARM debuff, and in a pinch Curse of Shadows can help you disengage. Perhaps more amusing is Phantom Hunter; now you can't HIDE from the big damn guns. There's potential here, one supposes.
Mortenebra
She can provide boosted attack rolls vs the living AND +2ARM. Bring in focus-efficient lights to take advantage of the free slams/charges, and add a unit or two...there's potential here, I think. And Morty's Repair[10] is solid as well, and in a pinch you can burn through her focus via Interface.
pSkarre
Dark Guidance and the feat are neat, but I think pSkarre still gets more mileage out of melee troopers. Not saying she couldn't run the Kraken, but I don't think it's optimal, and you're kinda hoping for good Ritual Sacrifice roles to make the most out of it.
eSkarre
At first glance, there are a handful of things that just don't work with the Colossal - Admonition and Perdition are out-of-activation movement that it can't use, and it cannot be directly protected by the feat. On the OTHER hand, Black Spot can let you rack up a HIDEOUS number of attacks and help them hit, while Seas of Fate helps you make the most out of the focus invested in the Kraken. Finally, Death Ward gets it up to ARM21 and can help preserve important systems.
Terminus
He can hide behind it and give it Berserk. Downside is it's expensive, but can make good use of focus Terminus gives it, and let's face it - you have this thing called 'Sacrifical Pawn' AND a CD-sized base to hide behind. Do you need to camp focus if you'll never get shot? Plus, berserk on a 4" melee range is hilarious.
Lich Lord Venethrax
Um. Yeah. Moving along...all Venethrax likes is hiding behind it, I guess.
Witch Coven
Going up to MAT8 SPD7 is nothing short of hilarious. Veil of mists can help with traffic control, curse of shadows can debuff ARM, and Nightfall can even protect this thing. The Coven can also generally feed it AND cycle Infernal Machine with their 9 focus. There's potential here.
Scaverous
ARM buff? Check. ARM debuff? Check. DEF debuff? Check. You have just about everything you'd want to support the Kraken, it's just a matter of using it at the right time and fueling the colossal.
Overall
On paper, I like the Kraken. I've played against a couple of colossals and don't find them broken; they're not THAT tough and melee heavies can still sort them out. Keep repair support near them, and keep away units of weaponmaster infantry.
I plan on trying the Kraken with eSkarre first up, and going from there. I'm pretty sure the Dennys will be fine, and so will Scaverous. The Goreshades seem marginal, and Venethrax and Gaspy are just kinda 'eh' for me.
