Blood Boil

In the Blood Death Knight talent tree, Blood Boil sits in the Blood specialization talents, row 2 of 11. It is a single-point node.

Connected above

The tree draws a line into Blood Boil from Heart Strike.

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  Heart Strike

  Instantly strike the target and 1 other nearby enemy, causing (196.7% of Attack Power) Physical damage, and reducing enemies' movement speed by 20% for 8 sec Generates 5 bonus Runic Power, plus 2 Runic Power per additional enemy struck.

Connected below

Blood Boil leads on to Bone Collector.

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  Bone Collector

  When you would pull an enemy generate 1 charge of Bone Shield. Surrounds you with a barrier of whirling bones, increasing Armor, and your Haste. Each melee attack against you consumes a charge. Lasts 30 sec or until all charges are consumed.

Same row

Also on this row: Marrowrend.

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  Marrowrend

  Smash the target, dealing (220.7% of Attack Power) Physical damage and generating 3 charges of Bone Shield. Surrounds you with a barrier of whirling bones, increasing Armor, and your Haste. Each melee attack against you consumes a charge. Lasts 30 sec or until all charges are consumed.