The Raven Guard keep their Chapter Tactic from Codex: Space Marines, but Kauyon gives them access to their own Warlord Traits, Chapter Relics, and Detachment, the Talon Strike Force. These are all limited to Raven Guard armies.
Talon Strike Force
The Talon Strike Force is another composite detachment made up of Formations, similar to the Gladius and Scarblade Strike Forces. The Talon Strike Force brings three really huge Command Benefits, which is great, since the Raven Guard are widely considered to have one of the weakest Chapter Tactics.
First is Extensive Planning. Talon Strike Forces can re-roll the die when determining Mission, Deployment, and when rolling for first deployment. For pick-up games, those are all pretty big. For tournaments where the Mission and Deployment are set, you still get to re-roll for first Deployment, and thus to choose who gets first turn. To my mind, this allows you to design your army as an MSU force, and re-roll if you come up with Purge the Alien, your one real weak mission.
Know When To Strike allows you to roll for your Reserves on the first turn, with them arriving on a 4+. This makes your Reserves much more reliable, and is particularly important for Flyers and Drop Pods (You'll get 75% of your Drop Pods first turn, rather than 50%).
Finally, Know When to Fade allows your units to choose to fail Morale checks. If you remember back to 4th Edition, this was the Combat Tactic rule for Space Marines, and you know how powerful this is. It allows you to choose to fall back from shooting or combat, getting your units out of dangerous spots. This definitely benefits your shooty units more, as your dedicated assault units would have to lose combat in order to make use of it. If that happens, the battle is probably going pretty poorly. Its main use is for squads to fall back when they take shooting casualties, getting out of range of enemy assault units. It can also help your units escape from close-combats that are going poorly, essentially filling the same role as Hit and Run.
Vanish into the Gloom turns your Warlord into a Warp Spider Exarch. Once per turn, when the Warlord's unit is targeted by shooting, it can immediately move D6". Any models that make it into cover at the end of this move get +1 to their cover saves against that shooting attack, and the enemy can't choose to target another unit. This could be quite frustrating to your opponent, as long as you keep your Warlord close to cover.
Concentrated Attack allows the Warlord to choose one enemy unit he can see at the beginning of each of your Charge Phases, and any of your units can re-roll charge rolls against that unit for the rest of the phase. This is a great way to ensure you can assault an important unit, and would be great in almost any other Marine army. However, Raven Guard units with jump packs (which will probably be any dedicated assault unit you take) can already always re-roll their charge distance, so this will only be useful if you take another kind of assault unit.
Master of Shadow allows your Warlord to choose to put the Night Fighting rules into effect during your Movement Phase, lasting until the start of your next turn. You can only do this once per game. Giving your whole army +1 to their cover saves during a crucial turn is nothing to sneeze at. If you use it first turn, your army will have +3 to their cover saves. This will neuter most enemy alpha strikes.
Silent Stalker makes the enemy take a Leadership Test in order to fire Overwatch against your Warlord's unit. Fittingly, they suffer -2 LD for this test if your Warlord charged through cover. I'm not sure how useful this trait really is, but it's great way to represent your Warlord bursting from concealment, unseen by his target. It basically turns him into Predator.
Exit Strategy allows you to add or subtract 1 from the roll to determine the end of the game as long as your Warlord is on the battlefield. This quite often can determine if you win or lose the game, and is a great trait. How often have all of us said "I would have won if the game ended a turn earlier/later?"
Swift and Deadly allows your Warlord and his unit to charge after running once per game, giving them pretty unparalleled reach for a Space Marine Assault unit.
Relics of the Ravenspire
The Armor of Shadows is a suit of artificer armor, which gives the wearer Stealth if he moved in the previous turn, and Shrouded if he didn't. Since these pass to his unit, this is a good piece of support gear. It certainly will do the most good when placed with a stationary unit, which will get Shrouded for the whole game. Even so, giving Stealth to one of your assault units isn't bad, especially as Raven Guard jump infantry can advance through terrain with minimal problems.
Ex Tenebris is an excellent bolter, having the standard statline but being Assault 3, Rending, and Precision Shot. It's quite cheap, and the fact that it's an assault weapon means that you can put it on a combat character without limiting his mobility. All you lose is the extra attack in close combat, so pair it with a specialist weapon (a lightning claw would be appropriate).
Nihilus is a unique sniper rifle, which can only be given to a Veteran Scout Sergeant. In addition to the standard sniper rifle rules, Nihilus is AP3, Armorbane, and Shadow-shot, which allows the bearer to target a different unit than the rest of his unit and makes the weapon S6 when fired at a vehicle. While Nihilus is a bit pricy, particularly because it also requires the Veteran Sergeant upgrade, it allows the bearer to reliably wound any infantry without a 2+ save as well as damage any vehicle (with an average score of 13 for armor penetration). Since the bearer can fire separately from his unit, it doesn't even waste any of their firepower. Nihilus adds a lot of firepower to a Scout squad.
The Raven Skull of Korvaad gives the bearer an extra point of WS and LD. If he dies, friendly Raven Guard models within 6" of his final resting place gain Hatred and Rage. This is handy for turning a Veteran Sergeant into a mini character, as the boost in WS can allow you to hit on 3+ against most targets. It's less useful on a Captain or Chapter Master, as they already have high WS and maxed out LD. The effect for his death is not likely to be important in most games, but it's a cheap relic, so call it a bonus.
Raven's Fury is a jump pack that adds +2S and Strikedown to the bearer's Hammer of Wrath attacks. These bonuses aren't great, but there's a very good reason to take Raven's Fury. It's the same cost as a standard jump pack, so these bonuses are free.
Swiftstrike and Murder are a pair of lightning claws that add the Flurry rule. This means that after the bearer rolls to hit in assault, they get an extra attack for each hit they scored. These bonus attacks can't generate more bonus attacks, but this is amount of bonus attacks is quite good. For example, a Chapter Master armed with Swiftstrike and Murder will have 6 attacks on the charge. Against most targets, he'll hit on 3+, meaning 4 hits, which will garner 4 bonus attacks, 2-3 of which should hit. He'll average 6.667 hits, with AP3 and Shred, which is enough to tear through most squads on his own. As a bonus, Swiftstrike and Murder only cost 5 points more than a pair of standard lightning claws. Their only downside is a lack of AP2, which means the bearer won't do much to anything with a 2+ armor save. He'll just have to pick his battles and target vulnerable enemy units, so he'll have to play exactly like Raven Guard are supposed to.
These rules give a big bonus to Raven Guard armies, and accentuate their ability to choose their battles and only engage when they have the upper hand. They excel at bringing on units from reserve exactly when and where needed (more on this when I review the Raven Guard Formations). I really think that Talon Strike Forces will see a lot of play in tournaments, particularly as Drop Pod forces. No other Space Marine army can bring on as many units as reliably on the first turn, much less give them all Shrouded to help survive return fire.