Board Thread:Warhammer 40k General Discussion/@comment-25507520-20150422230011/@comment-28917471-20150425074216

This is not how they will summon Ynnead. Each Craftworld need to fill in it Infinity Circuit with the souls of the Eldars,  when it will be full, Ynnead will be summoned.

And let's not forget that the ritual the shamans did was pretty risky thing. The Eldars take no risks with their life. If the Eldars would do the same thing the shamans did and it would not work... well... then their entire race would be tortured by Slaanesh for eternity.

Plus, their Craftworlds need to establish a contact with each other in order to do this ritual, and come to an agreement. Two things that will certainly be impossible to achieve.