Issaries is one of the most widely-spread cults in Glorantha. His markets appear in Kralorela, Fonrit, and Sog CIty. He’s worshiped as an ancestor by nobles in Seshnela and Maniria, he’s one of the Seven Lightbringers, and even has a Lunar daughter!
His magic is awesome. Create Neutral Ground spell facilitates communication between otherwise hostile people, making possible trade and dialogue even among enemies. Path Watch makes it possible to travel safely in dangerous lands. Lock and Passage secures goods, doors, and even city gates.
Issaries is scrupulously neutral in the disputes of others. Just let his caravans travel unmolested and we can all prosper! He’s friendly towards most everyone, and neutral towards the rest – only Chaos and thieves earn his ire. Heck, even Zorak Zoran cannot muster hostility to him!
The mule is his animal – more useful for carrying goods than a horse or Praxian beast, but acceptable by those that hate one or the other. His mule caravans carry goods across Genertela, and can even be found in Pamaltela.
He gets along with everyone! Associated with Orlanth, Etyries, and Eurmal, friendly with Argan Argar, Ernalda, Magasta, Yelm, and Yelmalio, he manages to remain neutral with the Red Goddess and the Seven Mothers. That is no small trick!
Issaries is one of the deities that makes Glorantha the distinctive place that it is. No mere God of Merchants – trade is just one of the tools he has at his disposal!
Note that Argan Argar is quite different from Issaries – even if folk often play him as a trade god. His magic is all about dealing with darkness and night. For example, Create Shadow lets you create an area of shadow that cancels out the sun. Suppress Lodril lets you screw with Fire/Sky/Light/Heat cultists (Caladra & Aurelion, Dayzatar, Lodril, Polaris, Yelmalio, Yelm, Yelorna, etc.). Safe lets you bar unwanted passage, similar to Lock but works differently. Plus a nice collection of Darkness Elementals and the ability to Dark Walk.
Who provides the donkey stallions and horse mares for breeding? Just like in the real historical world, donkeys are going to be found most everywhere in Genertela. Like in the real world, they are quasi-invisible compared to horses and Praxian animals. But donkeys are raised pretty much anywhere you find horses outside of the Pure Horse People.
The Issaries cult, through its caravans and networks of markets, allows members to maintain long-distance contacts and trade routes. And Tradetalk is spoken just about everywhere.
Issaries was definitely part of the Theyalan Council, although he did not hold a seat.