Awww come on, we can agree to disagree! XD
But back on topic; as mentioned above if you slot the KB-->KD Io into Torrent it becomes a very nifty soft control power!
Dark Blast also has the ability to stack a decent amount of to-hit debuffs on your foe, comes with a heal and a hold. It's always been more of a slowish DPS that relied on all its support and soft control abilities to make it useful. Probably why it took ages for the Devs to bring it to Blasters. As it's design runs pretty counter to the "in your face, everything must die now" playstyle of the Blaster.
I would love to do that if not for one thing; I am not a big fan of the stat bonuses that come with it. I would rather have a toggle that turns KB in to KD, if possible. But yes, there is that option if I get desperate enough...and I'm getting close, lol.
So don't slot the set. Put the KB to kd io with a 5 piece Ragnarok or posi and bob's your uncle.