User blog comment:Khalael/Building a Connection MkII/@comment-9734625-20110730225422/@comment-10514705-20110731041005

I see, but Syrath is reluctant to make allies. Among the few "allies" he tolerates are: individuals which serve a purpose (Bevid: Galvrak); stepping stones to power (he was a former member of the Antithesis) and his fanatical servants (Coraks: Arrius).

Therefore he would need to meet one of the above requirements to be an ally. Otherwise he would more likely be a rival. Also, don't count Syrath the Saint of Chaos as a Tzeentchian ally as he is only true allegiance lies with himself. Coraks and Arrius could fill the roles of Tardir's Khornate and Tzeentchian allies though.