I like that the MC separated from the ML eventually in order to figure out her own feelings clearly and not be another Stockholm syndrome type character. I dislike how abundantly OP the ML was. I think the author could have used the chance of the ML being in an unfamiliar place to inject some humor or give him some understandable flaws/foibles. Unfortunately, perfect!ML is perfect at everything and figures out how to drift a car just by watching people on TV.
There is very little in terms of redeemable side-characters. Pretty much every 'protagonist' that the MC beats in every world were secretly evil. While the novel's premise revolves around revenge, it would have been nice to see the formula changed up a bit; or at least the main antagonists changed up a bit.