Song of Suffering

I might be underestimating this card, but it never makes the cut for me. I like the free effect, and I love that it's Madness. It's just that my insanity themed decks would usually prefer methods of removing Terror icons and Willpower rather than ways to keep characters insane permanently. It's not the duration of the insanity that's the trick; it's driving a character insane in the first place.

I haven't played with/against Hastur insanity since the box came out, but I used to quite like this card. If you do manage drive an Ancient One or obnoxious Agency willpower guy insane, it's a lot easier to keep them insane with this then constantly re-removing willpower/terror icons. Each time you drive someone insane, you're spending resources. The more characters your opponent has, the more resources you're spending. This helps out a ton to limit what all you have to do, and always goes on their best guy.

 

Finally, there are popular cards (like Yog Peaslee) that you need to keep on lock 24/7, that just redriving them insane won't do the trick. Song of Suffering is the best tool Hastur has for that (the "destroy insane character" people are overcosted in more ways than one).