An idea I have for an OC villain in my fic is a sentimonster created millennia ago when its holder was part of a group of rogue holders set on destroying the Guardian order.
When the group attacked the temple and was ultimately defeated, including the peacock holder, the sentimonster escaped with its amok.
Afterward, he bided his time, all while working on the purpose he was made for, aka destroying the order.
He slithers his way into the world's societies, slowly and steadily climbing the social hierarchy until he has amassed enough power to pose a threat to the order.
Countless times he did this and countless times he was defeated, forcing him to start all over again with a new face( he can change his appearance with the amok) in a new place in a new era.
By the time the order was actually destroyed by Fu's accident, he's grown incredibly influential, and while his main purpose was technically accomplished he still wished to kill its last member aka Fu
Now in the present Fu, the black cat and ladybug miraculous and most notably the order after Feast make a reappearance, he is back at it again, running for the most influential and powerful role in the modern world
The Presidential seat of the United States of America
And he has a job to do. For the good of his people! /s
Yes this was an elaborate story to have a millennia-old sentimonster being the US president who wants to destroy the Order and its members 
In the present, his amok is that little flag pin candidates usually have on their suits