Al-Baghdadi, born Ibrahim al-Badri in Samarra, is an average Sunni Iraqi cleric with a degree in pedagogy from the University of Baghdad. His alter ago was born after Shock and Awe in 2003, and soon metamorphosed into a de facto serial killer - blowing up Shi'ite kids at ice-cream shops or scores of women at Shi'ite weddings.
ISIL's track record in Syria includes banning every flag apart from its own; the destruction of any "polytheist" temple or sanctuary (except if it is Sunni); and strict imposition of Islamically correct women wear. Most of all, it is a track record of terror. This is not an army, rather a well-trained militia of professional mujahid, European passport holders included, with battlefield experience in Iraq, Afghanistan and, to a lesser degree, Chechnya. Heavy weaponizing is petrodollar-financed - the usual, wealthy "Gulf donors", which does not exclude official connections.