What is the ruling on taking Hadith from deviant sects, such as the Rafidah, if the Hadith is considered authentic by the Sunnis, like the Hadith that prove the treachery of the innovators of Kufa against the Prophet's Household?

It is not permissible to attribute fabricated or false hadiths to the Messenger, peace and blessings be upon him, even if they serve as an argument against innovators, because the authentic hadiths suffice in this regard. Whoever narrates a hadith (definition) while believing it to be false is one of the liars. It is forbidden to narrate a fabricated hadith for anyone who knows it to be fabricated, except if its fabrication is made clear.