On his Facebook profile page Omarkhayam Romato Maute describes himself as a "Walking Time-Bomb."
When a band of militants led by Omarkhayam and one of his brothers overran a town in the southern Philippines on May 23, festooning its alleyways with the black banners of the Islamic State group, the Facebook description seemed appropriate.
Governments across Southeast Asia had been bracing for the time when the Islamic State, on the back foot in Iraq and Syria, would look to establish a "caliphate" in Southeast Asia and become a terrifying threat to the region.