What is the ruling on someone who denies the narrated Hadeeths about the Mahdi and the Antichrist?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

There are numerous Hadeeths that have been narrated about the Mahdi and the Antichrist so they are considered to be Mutawaatir (continuously transmitted by a large group)  Hadeeths  (which is the highest form of authentic narrations). This opinion was adopted by the scholars of Hadeeth such as, Al-Haafith Ibn Hajar Al-‘Asqalaani, As-Sakhaawi, As-Saffaareeni, Al-Kittaani, Ibn Hajar Al-Haytami, and Ash-Shawkaani .

Ash-Shawkaani stated that he had found fifty narrated Hadeeths and twenty-eight traditions (from the companions) with regard to the Mahdi.

Mentioning some Hadeeths related to the Mahdi, Ibn Taymiyyah pointed out that some sects went astray with regard to these Hadeeths. One sect rejected them, supporting their opinion with a Hadeeth in which the Prophet, sallallaahu ‘alayhi wa sallam, said that there was no Mahdi other than ‘Eesaa ibn Maryam (Jesus son of Mary) . [Ibn Maajah]

However, Ibn Taymiyyah clarified that this Hadeeth is Dha‘eef (weak-inauthentic).

Ibn Hajar Al-Haytami issued a Fatwa that if anyone rejects the Hadeeths of the Mahdi due to denying the whole Sunnah, then he is a disbeliever. However, if his denial is out of obstinacy to the words of the Imaams of Islam, then the Muslim rulers should subject him to an appropriate punishment.

And Allaah Knows best.