America's New Bomb-making Supervillain

How ruthless is this new supervillain? He sent his own brother on a high-profile suicide mission to take out the main dude in Saudi Arabian intelligence. The mission failed -- simply because the bomb exploded downwards, killing only the younger Al-Asiri -- but the fact that the young brother was able to make it so close to the head of Saudi Arabian intelligence only proves the true evil genius of the two brothers. Had the mission succeeded, Ibrahim Al-Asiri would have become the most wanted man in the Middle-East, but instead he was only given a bigger motivation to continue fighting; his brother died without accomplishing his mission.
Al-Asiri's genius lies in his ability to make undetectable bombs. The bombs use PETN -- a largely common and easy-to-detect-by-dog explosive -- but placed inside of underwear, it's very difficult to detect during a patdown. The PETN comes into contact with an acid which sets it off, thereby negating the use of metals for a fuse or for a remote detonator. Also, since it takes time for air particles to seep through a sealed, specially-designed container, it may not be possible for dogs to detect PETN until many hours after it has been sealed. Though most of the more famous bombs built by Al-Asiri have failed, he has had plenty of time to perfect his craft, and has allegedly gathered an army of proteges in the event that he is killed by drone.
According to reports, Al-Asiri has been busy working on the development of implantable explosives. Al-Asiri has been studying the tactics used by Latin American cartels to smuggle drugs, and has likely devised pills of explosives that can be swallowed, with the explosion being set off by the stomach's own digestive work. This represents an even bigger threat than before because with training, the stomach's capacity can be greatly increased.
In United States vs Montoya De Hernandez, Ms. Montoya was found to have swallowed 88 balloons of cocaine, to the extent that she appeared pregnant. This means that a stomach bomb with the equivalent amount of PETN or Semtex could level a substantial structure regardless of how well-reinforced the structure may happen to be. This is the future of terrorism in the world of explosives, and it is only a question of time until extremely powerful bombs can be smuggled into any place that does not have a sonogram machine.