WotLK Demonology - Decimation talent

[Ghortan2]

Hi,

I noticed something going on with Decimation and I don't know if this is normal.

Let's say Decimation procs, I wait a bit and the proc is about to go off, like 3 seconds left. Then I start casting Soul Fire, which of course has the casting time reduction on, so it's more or less a 5 seconds cast. Now, before I finish casting Soul Fire, the Decimation proc wears off. After a few moments, Soul Fire begins to fly. This is where I noticed that even though I started casting Soul Fire with Decimation on, the spell still uses a Soul Shard, while benefiting from the reduced casting time.

Is this supposed to be this way?

[Dozorto]

It IS this way
Which means, to min-max dps in a raid, you gotta have the maximum of 32 of shards at all time. Many times you will find yourself proccing decimation off adds, casting soul fires and losing a shard every such time.

Soul Fire checks for decimation on the cast's start, while destroying a shard by the end of it. Everything in order.

[Ghortan2]

It IS this way
Which means, to min-max dps in a raid, you gotta have the maximum of 32 of shards at all time. Many times you will find yourself proccing decimation off adds, casting soul fires and losing a shard every such time.

Soul Fire checks for decimation on the cast's start, while destroying a shard by the end of it. Everything in order.

I see. Thanks for your answer and the tip.