The Fate-Rewriting Ghost Hunter

After eerie nights descend, supernatural anomalies run rampant after dark. Delivery worker Finn Lane takes a job to enter a haunted building to treat his seriously ill sister, and accidentally activates a system: the Rule Modification System, which can rewrite supernatural keywords. He is also forcibly bound to the SSS-class sharp-tongued wraith Devourer Wraith, and inadvertently becomes a Ghost Hunter.