Backstory
As one of many different Reincarnation Gods, Isi has their own separate world for those that they shepherd under their care. When humans pass away, Isiktan decide if they are worth reincarnating into another life in the mortal world, whether it be as a part of humanity or nature. Bad behavior in a past life can result in a unsavory life to teach humility, not that the reincarnated person would be aware. To those with truly humble souls, living earnest lives repeatedly, Isiktan invites their souls for rest in their world, turning them into deer that reside and idle in their world. It's a straightforward job that is malleable by Isiktan's opinions on each person they judge, but there were times where too many humans died and managing was becoming bothersome; the initial escape of the Miseries in the mortal world nearly wiped out humanity. When Isiktan was made aware by other Gods that these malevolent Gods were made simply to extort more desperate faith from humans, Isiktan was very upset about it if it impacted them. What faith is there to gather when many die? Sealing the Gods manually was a task entrusted to Pandoras, eventual damage control devised by the Gods that made the Miseries, but Isiktan wasn't going to wait around until their job got easier. Pandora's were partially human, blessed humans, so they could still die during their work. At least, when the Miseries did leave the original Pandora's box, Eden was found within it. The Hope of humanity, she could cancel out the effects of the Miseries, minus curses, so Isiktan trained her personally as she grew up. She was still too young to defeat a God on her own at the time, an unexpected battle with Ephialtes, Merikh, and Pagule leaving most of the work to Isiktan.
By this point the Miseries existed for hundreds of years, Isi many more, powerful enough that Isiktan could only use a certain amount of their own reincarnation abilities to harm them. Because the evil Gods couln't be reincarnated fully, their power was taken away enough to leave them as children, but that included Isiktan. The weakened Miseries fled to the Divine World after their loss, which is the world the sealed Miseries would have been hidden in anyway, taken there by Pandoras if captured. It's a world where many humans also reside in if they are spirited away by Gods, simply having to coexist there with the supernatural and building their own lives. Unfortunately, Isi realized how much more of a disadvantage they found themselves in after that battle; They needed to train Eden, to keep up with their work even, so it wouldn't hurt to enlist further help. Taking two reecently deceased twins, Maite and Matia, Isi made them their underlings as Incarnates. The pair had been good natured as humans, reincarnated about 9 times by Isi, always together. Isi allowed them to retain the memories of all their lives, each with a different job in the afterlife: Matia would hunt the scattered Pandora's boxes before other Miseries, and Maite would continue to shepherd humans into the Divine world for their next steps. This was a great help for Isiktan, but there were always a few worries over the Incarnates whether they said so or not. Essentially, keeping a human around for too long could make them feel out of touch with their humanity, becoming desensitized to terrible things that the Gods are used to. In turn, Isi personally felt a little bit more "human" after exposure, compassionate and more aware of strong emotions, but that isn't necessarily a bad thing.
Hearing about the apathy Merikh and Pagule hold is understandable, given that they're unwanted beings in a life against them, but Isiktan can't let them become stronger if their end goal is to decimate humanity entirely, then make the Gods themselves kneel before them. They're a duo with a Pandora's box each, items considered something of a portal between the mortal world and the Divine World. When Gingko insists on becoming involved, Isiktan is annoyed finding out that Ephialtes is still seemingly causing some kind of trouble, adding more to their plate. Still, Gingko is needed to draw out the human that is being possesed by a Misery, something that shouldn't happen unless permitted by both parties. It's strange, but there must be a reason. Regardless, Isiktan only needs to focus on sparing humanity as a whole, no matter what world they're finding themselves in.