Faqeer Bagh Hussain Kamal (RA) mentioned in his Khutbaat that there is a detailed Hadith about Imam Mahdi (AS). After getting this hint, A detailed Hadith Mubarika comes to our knowledge from Hadith Book Sunan Ibn Majah. May be Faqeer Bagh Hussain (RA) referred to some other Hadith, but most probably this is his referred Hadith due to its detail.
Please note, Sunan Ibn Majah is one of Six Major Ahadith Books (Al-Sihah al-Sittah, which translates to “The Authentic Six”) so this is an authentic Hadith. Also remember, Quran & Ahadith are most authentic sources for a Muslim to envision future events
A detailed Hadith Mubarika about Dajjal, Imam (A.S), Hazrat Isa (AS) and many events which will occur in future.