The art feels pretty familiar

reminds me of the villainess within but the plot and characters are flat

Same thoughts. It's from the same artist, but the plot is a bit meh ╮(￣▽￣)╭... Right now I found a BL manga very interesting , in case you liked The One Within the Villainess, it's called "Doku wo Kurawaba Sara Made" ლ(´ڡ`ლ)