It's an original work that the that uses expies of established isekai characters. The Yuuto expy is meant to a deconstruction of the character, so changing it too much might miss the point.
Is it okay if some of his harem being underage is just mentioned?
The heroes from Master of Ragnarok and In Another World with My Smart would work as villains since many of the criticisms of the isekai genres actually apply to them.
Women fall in love with Yuuto upon meeting him for flimsy reasons and his harem has little girls. I'm not sure how I'd go into...
My husband, Thoth. He's an Egyptian deity like myself. You can't miss him. He has an ibis for a head. He's the god of the moon, wisdom, writing, hieroglyphs, science, magic, art, and judgment.
I've got a picture of him here...
I'm thinking of doing an Isekai story. I thought up this idea after I found out about Cheat Slayer and it's shallow parody nature.
A guy gets hit by a truck and reincarnates as a half elf/half demon. His new father would be an Isekai Slayer, who's job is to hurt and kill people who have crossed...