"Redemptory" refers to something that provides redemption, salvation or deliverance from sin or error. As an antonym, "less redemptory" would indicate something that fails to provide these qualities, or perhaps even exacerbates the situation. "Harmful," "dangerous," and "destructive" could be used as antonyms, suggesting that the actions or qualities in question are not redemptive, but rather harmful or even detrimental. Other possible antonyms could include, "condemning," "punitive," "vindictive," or "judgmental." Essentially, any term that indicates a lack of salvation or redemption could be used as an antonym for the phrase "more redemptory.