Did Abdullah al-Harari al-Habashi serve Islam or demolish it?

The man mentioned is one of the leading figures of innovation (bid'ah) and misguidance in this era. He has dedicated himself and his followers to undermining the creed of Muslims. They have compiled for themselves a corrupt school of thought in jurisprudential matters, filling it with every aberrant and reprehensible statement that has no basis in the Book or the Sunnah. They also have numerous grave errors in matters of belief and practice, and they disparage the imams of this religion. Therefore, it is obligatory to be cautious and to warn against this deviant sect and its misguided ideas.