This time, the topic says it all
What provides -Edge of the Abyss- about the Saynay Clan?
Well I cannot comment about Edge of the Abyss but there is a little bit in Battlefleet Kronos about the clan - it mentions their flight from the Calaxis sector into the Expanse, and some of the ships it now has in its fleet including a true warship, thanks to their alliance with a renegade navigator Ember Nostromo. The ship is a Retaliator Class Grand Cruiser no less!
Hope it helps!
DW
Hi Traveller61,
thanks for the reply. Does "Battlefleet" contain any informatin about the Saynay Clan itself? Like how they are, stats, customes, their origin, believes... you get the picture 
I can't remember if it's the Saynay clan specifically but there is a section of Edge of the Abyss devoted to the Chaos forces roaming the Foundling Worlds.
I think the details of Saynay Clan, the cannibal sorcerors of chaos, can be found at Edge of the Abyss. Some new psychic powers; several pages only about this clan; and statistics of Saynay Sorcerors or something like that.
Most of the infortmation is in Edge of the Abyss. I think it's two or three pages, and a picture or two. Mostly it mentions that their leaders are fat blood stained dandies who lead cabals of witches as they seek out other places to plunder and people to eat.
What little information there is in Koronus revolves around what types of ships they use, as well as mentioning they do have a grand cruiser allied with their otherwise ramshackle and undergunned fleet.
There's also a couple of entries for specific ships in Vall's fleet, plus an independent ship or two to go along with more 'generic' stats for typical reaver and chaos ships.
In fact, one of the BFG chaos destroyers is in the regular ships section with a bit of fluff to explain its use by both imperial and non imperial factions.
The information on the saynay clan in EotA is only one third of a page (p. 80). The rest of the section on the Chaos Reavers is mainly devoted to Karrad Vall and a small bit about the damned hosts of iniquity. The information in BFK (p. 103) is actually slightly larger, but still only half a page.
So, it is by no means worthwhile to go and buy a book for it. Thank you, all!