The level 75 talent depends on the encounter, as it provides no boosts to either survivability or DPS directly.
The level 100 talent can be changed if survivability isn't an issue, and you want to bring more DPS to the encounter.
Heartbreaker : Increases the runic power generation on
Heart Strike by 3 for each target hit. This is a very powerful talent, as runic power is necessary for both DPS and survivability
Bloodworms : Has a chance to spawn a blood worm on critical strike autoattacks, that then burst after a given amount of time, or when you drop below a certain health threshold. This provides a safety barrier to counteract spike damage, but proves weak due to the relatively high threshold and their low duration.
Blooddrinker : Gives a new ability that channels on the target, draining health from them and healing yourself. Unfortunately, this talent is simply tuned too low to be useful, and should never be taken.
Rapid Decomposition : Increases RP generation while standing inside
Death and Decay, once again giving a boon to survivability and DPS, as well as increasing the damage done by
Death and Decay.
Soulgorge : Theoretically allows active rune regeneration, giving a new ability that lets you consume nearby applications of
Blood Plague, increasing runic power generation. By removing the application of
Blood Plague on
Blood Boil, though, this talent makes the class significantly harder to play on AoE, and offers little benefit overall
Spectral Deflection : Allows your
Bone Shield to consume an extra charge when taking high damage, providing a buffer for spike damage. It can be taken when the risk of dying is extremely prominent, though generally
Rapid Decomposition is better.
Ossuary : Reduces the cost of
Death Strike by 5 Runic Power when at 5 or more
Bone Shield charges, as well as increasing max runic power by 10. This talent effectively allows much more frequent Death Striking, synergizing very well with talents that increase RP generation, and talents which improve
Bone Shield effectiveness.
Blood Tap : Allows you to actively regenerate runes by using the ability, the recharge time of which is determined by the consumption of
Bone Shield stacks. It puts more control over your resources in your own hands, effectively allowing you to generate runes when you need them most.
Anti-Magic Barrier : Adds an extra component to
Anti-Magic Shell, increasing your current and max HP by 25% on use. This talent can be extremely powerful in the right circumstances, and can be used to add an extra cooldown in situations where dying quickly can arise.
Mark of Blood : Gives an ability that, at the cost of 30 RP, allows you to mark an enemy, healing anyone they auto-attack by 2%. This talent, while providing passive healing, gives a very small amount overall, and the runic power is almost always better spend on
Red Thirst : Is a very powerful talent that decreases the cooldown on
Vampiric Blood by 2 seconds for every 10 Runic Power spent.
Vampiric Blood is our most versatile cooldown, and having more uses of it extremely valuable.
Tombstone : Is another talent that puts resource management in the player's control. It allows you to consume Bone Shiled charges to generate Runic Power and to put a shield on yourself. Unfortunately, the talent has strong anti-synergy with
Foul Bulwark, along with resulting in an overall loss of Runic Power compared to playing without it.
Tightening Grasp : Decreases the cooldown on
Gorefiend's Grasp by 1 minute, as well as applying a slow effect to your
Death and Decay. This talent will be the go to choice for any encounter that requires frequent use of
Gorefiend's Grasp, but is useless if that is not the case.
Tremble Before Me : Gives your
Death and Decay a chance to cause enemies to cower in fear for 3 seconds, occurring at most once every 10 seconds. Damage will break this effect. While this talent has potential for randomly interrupting casts in an AoE, it proves lackluster and currently has no place in any raid or dungeon encounters.
March of the Damned : Increases the duration in
Wraith Walk by 50% and causes it break various Crowd Control effects. When gripping is not required in a fight, this talent is extremely good, as tank mobility is a necessity, and is the area
Death Knights are weakest in.
Will of the Necropolis : Provides a damage reduction when reduced below 20% HP. While this is a powerful talent, the current HP cutoff is extremely low, making it proc very rarely, and have the player in an already very dangerous situation when it does.
Rune Tap : Adds an additional cooldown, reducing damage taken by 25% for 3 seconds at the cost of 1 rune. While not recommended if using
Ossuary, it is the best choice if taking
Foul Bulwark : Is the strongest talent in this tier, increasing your HP by 2% per bone shield charge. Synergizing very well with
Ossuary, it provides a constant boost to survivability during an encounter, outweighing the occasional boosts from
Rune Tap and
Will of the Necropolis.
Bonestorm : Gives a new ability that consumes up to 100 Runic Power when cast, giving an AoE effect around the player for 1 second per 10 RP spent, up to 10 seconds. The damage is deals will also heal you, giving it insane healing potential on large packs. Its survivability gains, though, are hindered by its long cooldown. It is the best option on this tier for AoE DPS.
Blood Mirror : Gives a new ability that reflects 20% of the damage taken back to the attacker for 10 seconds. Best used before choreographed high-damage abilities, this talent is the best pick for single target DPS this tier, but is lackluster for survivability.
Purgatory : Will prevent you from dying once every three minutes, instead applying a healing absorb for the amount of damage taken. If you're healed out of the absorb within 3 seconds, you will live, otherwise you will still die. This is the best talent to take for progression in this tier, as it will prevent countless deaths.