Fateweaver is necessary to make the ScreamerStar effective. 1/9 failed Grimiore thanks to his reroll plus a reroll on the Warp Storm Table.

That being said, ScreamerStar is not a reliable list for winning large tournaments for a couple of reasons.

The Star is unreliable: Listed in order of liklihood.

50% chance opposing player gets to go first and shoot the ScreamerStar.

Forewarning is not a guarantee. Maximum chance of success assuming two rolls and a Flickering Fires Primaris for the third choice on four ML3 Heralds(510pts minimum). 20% of not getting Forewarning. Can be higher at the cost of Flickering Fire, Maximum of 94% chance for forewarning at the cost of all Flickering Fires. Most will not be running four Heralds, 3 is more likely, 30% and 12% respectively.

11% chance of failing the Grimiore.

LD10 Psychic test has a 8% chance of failure. Yes, they manifest at Ld+3, but Ld can not be increased beyond 10.

A single RunePriest stands a strong chance of stopping the list and what SW player is bringing only one?

A single GK Stormraven is capable of sniping the Grimiore Holder thanks to PitW, two is very likely to.

An opposing Grimiore can just as easily nullify your ScreamerSstar.

SitW hurts.

Grimiore Holder can be sniped out and does not benefit from the Increased Invulnerable Save.


Now, in games where everything goes as planned the ScreamerStar is virtually unstoppable, difficult to tarpit, and capable of pacmanning an opposing list. It takes a very good player to be able to mitigate all of those potentials to fail ie deployment, placement, tactical retreats, etc.

Over the course of a 5 game GT, the Screamerstar is likely to fail against one opponent and good opponents will capitalize upon that mistake. In standard, the Screamerstar is 890-1035pts for the Screamers, Fateweaver, and three or four Heralds.

IMO FMC spam and Grimiore multi Khornedog Rush is scarier and more reliable IMO.