battletome up at black library
from the free preview we can see that
-lizardmen reached azyr following the tears of dracothion who, in mind-communion with the slann, learnt of the loss of the old world and was crying for it
-lizards may have in fact reached the mortal realms way before sigmar
-each star in the constellations represents a host/or a great hero of the lizardmen
-while the chaos gods don't learn from fighting the lizards, the slann have thought and planned to crush them to build an universal order to things and are enacting that plan
-the attacks of lizardmen intensified with the waves of sigmarines
-the slann do prepare things so much that they are said to always be many steps ahead of their enemy
-while being summoned by the memories of the slann, the lizardmen are immortal spirits and will continue to fight and continue a battle even after the death of the slann that evoked them (meaning that they're not completely dependant on them as it may seem at a first sight)
-this independency is further suggested by certain descriptions of units from the site, like the skink starseer (tetto eko) which show that the lizardmen act and think in a way sometimes different from that of the slann, meaning that they're not mere illusionary thought-constructs
this until we get to see the battletome in its entirety to read up all the details
I for one welcome our newfound ascension in the crucible of stars