You are prime minister of a certain country that was former aligned to the order. Since your country transisted into monster friendly state you expect the male populace would just ride into it but instead it led to the rise of doomers wwyd?
In all likelihood, these doomers have leaders or spokespeople. Meet with them to hear them out. It's entirely possible they're being led astray by propaganda from the Order. After hearing and considering their grievances, arrange a meeting (or several) with representatives of the mamono community to establish a dialogue and work to smooth out the problems.
The Fact that these people exist may stem from past trauma, I imagine early childhood, teenage years etc. perhaps a subtle approach from Mamono may allow them to open up, express there shared grief and allow them to be free of their troubled past. wouldn't that be a preferred outcome?
Propaganda. And show them they're fucked up with my ability to gourvament.
If they start to rebel or terrorist. I destroy the rebellion and executed them quickly. But the way to execute the terrorist is brutal and public to bring fear. And not the Mamono who done execution, it's done by human. To show them human are acually demons and not to bring fear toward mamono.
And for the Mamono side, I rule them to become more gentler to men. To bring thrust. And I could crate the new Religion that believe that Mamono and Human could co-exist.
I will have to trigger many scientific revolution done by Mamono as fast as I can. I will have to make Mamono product men, to cause Mamono and Human that Mamono wouldn't bring destruction. Plus, I could make use of DNA altering to improve new gen and show the capbality of them to crush doomers's brain. And scientific evolution would be suited with my new religion. And the people will stop belived in chief god due to uncivilized trait they got. They will focus on something civilized like my new Religion combined with science.
Bonus, sine I have scientific revolution and new religion. The Order will see me raise in power. And that's why I prepared my supermacy toward those Fanatix Xenophobe Orders. Not only Xenophobe, Fanatic Purifier too. And I will bring my supermacy to counquer them with new weapons and unity I got. And I will show the Doomers that Order will hopeless. And once the order in that area gone, I repeat the method ealier.
Look like I love to crush their mental...If the cancer grow in body, to save lifes, it need to obilirate as soon as possible.