
Originally Posted by
Morningstar1337
Pardon me, but didn't Ysayle prove that a cult of similar numbers can summon a primal?
Technically she didn't form the heretics though in so much as just came in and gave them a leader to get behind, as it appears the heretics have been around since... well, since Ishgard's founding. Also Shiva was
created from Ysayle's own misguided beliefs and desires based on the few snippets of Hraesvelgr's memory of the real Shiva she glimpsed through the Echo - all she had to do was then use the heretics' hatred for Ishgard and how Shiva was reviled by the Church of Halone.
Incidentally, we don't actually know how Ysayle came into the knowledge of summoning - but Ascian influence is the most likely cause.