Monitoring the doubts of Mahdism in order to dispel doubts is a necessary fact. In recent decades, the efforts of the opposing media to depict a harsh face of Imam Mahdi (a.s) has increased. The present paper criticizes the suspicion on the extreme killing by Imam Mahdi (a.s). This suspicion has been raised by Ahmad Kateb in a program entitled “Shah Kelid”. In his extreme view, Imam Mahdi (a.s) starts massive and horrifying massacre and his behavior does not resemble that of the Holy Prophet (pbuh). The purpose of the research is to present a criticizing attitude towards the mentioned suspicion and an analytical answer as well. To realize the purpose, we have made use of qualitative method of thematic analysis in semi-structured documents (live programs being broadcast) as well as published works. The technique used in this paper is analyzing the narrations in relation to the decisive encounter of Imam Mahdi (a.s), based on the logic of understanding hadiths of Mahdism. The findings of the research indicate that Kateb’s approach towards narrations on vast and extreme massacre is meant to impair the face of Mahdism. Classifications of the narrations presents us with a logical reading of Imam Mahdi’s biography and their summary results in the strengthening of correct belief in Mahdism and avoidance of the view on extreme massacre by Imam Mahdi (a.s). The authoritative encounter of Imam with the opponents is few in number and is carried out at the last stage of action, because his work at this stage is considered as an example of God’s mercy for the society.