First, you need to come up with a unique and interesting character design for the villainess. Make her have complex motivations and personality traits. Also, think of a captivating plot that keeps readers engaged.
Well, 'A Villainess for the Tyrant' manga is appealing because it offers a fresh take on the typical romance tropes. The world-building is also quite impressive and draws you in.
For me, 'That Time I Got Reincarnated as a Slime' stands out. The world-building and plot development are really engaging. Also, the characters have a lot of depth.
Well, it's a bit hard to pinpoint exactly which was the very first one. But some early examples could include 'El-Hazard: The Magnificent World', which had elements of the isekai genre.
The main problem might be the struggle to change people's perception or the difficulty in finding true allies. Plus, there's often the burden of living up to the villainous image while still trying to have some depth and complexity.
Perhaps it's a way for the author to explore different themes and challenge conventional character archetypes. The decision for her to be a villainess might be to create tension and drama in the manga's narrative.