Runes are currently extremely bugged, at least in regards to Death Runes. When Death Runes are active, they are being ignored as cost components for abilities like Howling Blast and Death Strike. Those abilities will wait for a set of Frost and Unholy Runes to come off cooldown before attempting to use any Runes for abilities. It seems like Death Runes are set to a low priority for consumption, however that low priority is below even Runes on CD. This completely breaks the Death Rune mechanic and makes them less than worthless.
Easy way to replicate:
- Have Blood Strike and Death Strike on your Action Bar
- Use Blood Strike Twice (placing Blood Runes on CD and converting to Death Runes), wait 2 seconds
- Use Death Strike Twice (placing both sets of Frost and Unholy Runes on CD)
- Wait for both Death Runes to come off CD
- While Death Runes are off CD and Frost and Unholy Runes are on CD, observe Death Strike has a CD matching the earliest completed set of Frost/Unholy Runes