Due to the uprising that happen years ago because of a rouge Reincarnation's selfishness many innocent people were killed and slaughter in the name of a revolution. MC now treats all Reincarnations as potential seeds of disaster regardless of intent, and their existence in the world an anomaly that needs to be purged.
Seen this story trope before, not sure how it will pan out fully. Will they do the stereotypical MC begins to feel remorse and sympathy for the Reincarnations, will the protégé or trainee Purge Knight sympathies with them instead and put the MC in a hard place of having to purge their own student they've grown attached to for aiding Reincarnations, will they do another thing where the MC has not always been killing Reincarnations as he's been told and was actually killing normal people who were deemed problems by the state/church.
Don't know for sure how the author will build off the premise, or if they will just stick to usual tropes of this deconstruction of isekai genre from the perspective of an isekai world's residents.