Seeds of Despair
It’s been mentioned several times that Mael is
a) absent/disinterested in general
b) neutral/ambivalent in the war against the CG.
And so his followers are left free to take whatever position they like. And they do.
Jhistal: a high priest of an Elder God who employs human blood in ritual magic (Elder equivalent of a Destriant)
“In this way,” Mallick Rel said, spreading his hands, “necessity is an economic matter, yes? That an ignorant and backward people must be eradicated is sad, indeed, but alas, inevitable.”
“You would know well of that,” Tavore said to him. “The Gedorian Falari cult of the Jhistal was eradicated in a similar manner by Emperor Kellanved, after all. Presumably you are among the very few survivors from that time.”
Mallick Rel’s round, oiled face slowly drained of what little colour it had possessed.
The Adjunct continued, “A very minor note in the imperial histories, difficult to find. I believe, however, should you peruse the works of Duiker, you will find suitable references. Of course, ‘minor’ is a relative term, just as, I suppose, this Wickan Pogrom will be seen in later histories. For the Wickans themselves, of course, it will be anything but minor.”
I believe the reason why Kelvanned wipedout the Jhistal is mentioned in either BH of RCG, theres a quote somehwere along the lines of: Kelvanned saw what the jhistal had done and was disgusted, and then proceeded to wipe them out as an offence to all that was decent in the world. So if kelvanned thought it was inhuman it must have been pretty bad.
I do recall this quote he mentions, about the emperor being discusted with how the cult abused the notion of faith and worship to usurp Mael and control him. And I think that is why they have had so much control, it is mentioned that they are the ones who kept him alive/remembered by their worship and if nobody else did so I guess that is what gave them immense control over Mael.
The Jhistal were a cult who developed a system where they worshipped Mael, but twisted this worship through rituals so that they controlled him, perhaps similar to the bindings placed on the resurrected elder god in MT. This binding almost certainly revolves around blood sacrifice, I suspect the bloody sea mentioned in LoLE, where many ships are killed might have something to do with this ritual.
I think the main focus of the jhistals power over Mael, is that by providing a focus for his worship they become responsible for a large part of his power, and so exert control over him. The fact that mael may not want this power is irrelevant, mael indeed has to fight his power in some instances, see when he had to fight against the bloodthirsty wishes of his worshippers in order to heal.