When an attack drops your health below 35%, one of your Blood Runes will immediately activate and convert into a Death Rune for the next until cancelled. This effect cannot occur more than once every 45 sec.
Item - Death Knight T13 Blood 2P Bonus
Player takes auto attack (white) melee damage
Player takes special (yellow) melee damage
Player takes auto attack (white) ranged damage (with a bow, etc)
Player takes special (yellow) ranged damage (with a bow, etc)