Review Detail of Darkmishas in The Villain's Wife

I finish reading this story. I love the characters & plot of revenge , schemes & face slapping. I love the love that ML had for the FL. unfortunately the ending ruin the entire story. I was disappointed & found the ending to be unrealistic & doesn't fit with the story plot. how did a wonderful revenge story that took up 90% of the story turned into a sci-fi of mutants superpower & immortality ??? the last 20 chapter feels like an alternative reality or dimension of Earth. it just doesn't make any sense & the happy ending for our MC was gone. if the Author had wanted to introduce Sci fy there were other ways to do it that could flow better .