I was thinking that the Church worship an adapted version of the actual Gods (In a similar fashion to Alessia's Pantheon).
I'm considering making him slightly delusional, believing the dragons are the true Gods and that they will wipe out the Church alone and rule atop the world in their rightful place.
I feel bad for the God-Monarch now. To be stolen from your parents, then trained harshly to become a manipulated ruler. If he steps out of line, he will probably be crushed. I'm guessing the people would call him Yor, like all GMs, but it might be good if he sides with the main character, wishing to escape this jail he has been forced to rule, and become himself.
And for names, I suggest you sift through here to get them. I used it to get Renoldus.
Young, but certainly not uninformed about how cruel the world is, I want to avoid a "family killed by <insert enemy here> cliche" for this, maybe he just sees things for what they are? They have good wishes, but aren't afraid to do small evils for the sake of the greater good (No villains on ledges going "if you're such a hero, you won't let me die", he would kill them).
The main character won't, as he will already be more powerful from the Un-Gods blessing/curse. The Adviser would certainly be more of an antagonist if he did, so I'll probably do that. As for Renoldus, I could change the lore slightly and make it so that the God-Monarch is only kept if he shows affinity in the Lightning Elemancy and is born on the same day of the God-Monarch's death.
Gremlins would amuse me, and probably not work, but still...
Names for the advisor are Vauquelin, Ivo, Dryke, Elspat and Merilda. The first 3 are male, last two are female. These were got off the medieval generator, which will probably be of the most use to you for the church names.
Unfortunately, the bounty hunter generator generates nicknames, which could be used, but are not as useful as an actual name.
Gremlins, Elves, Goblins and Dwarves have been completely avoided, since they've been done to death in fantasy in my opinion (not saying I don't like them, I do, but avoiding cliches is a big thing for me right now).
I like the names Ivo and Dryke, personally.
I'll see what I can do for the main character name.
I agree with him on the ratmen, not sure about the others.
Ratmen (Achavens?):
Servants of the Hags or Corrupted merchants who have struck a deal with the church, they could occupy a bordering country, that has been warring with the character's country for a long time. Possibly conquered, and added to the empire
Also, for the Gm, you could make several children picked. It would be a traumatic experience for him, watching his fellows be killed off one by one as they fail to achieve the Churches ambition. He could be guilty, and mourn for them, feeling his hands are as dirty as theirs.
You could make the Church corrupt before the reign, so he is aware but too afraid to do anything about it, or he will be mercilessly crushed and another picked.
If and when I write a sequel I do have an idea for some kind of animal men.
Yes, that's a good idea, that'd make the odds of finding a child with Elemancy easier, since they aren't exactly common.
They were, remember that the selecting means that there is at least an 18-year gap between Monarchs.
How about something like this: each adviser has an apprentice who they teach to control the church and keep the God-Monarch unaware, they are the true rulers, the God-Monarch is an idle figurehead.