One who is deliberately & pig headedly uncooperative in persistently pretending that he fails to understand the glaringly obvious with needlessly destructive results.
It is a curious point that such a complex concept should have a single word to express it.
Presumably there were or are enough amballadi (pl.) in Cyprus to justify giving them a word all to themselves. Even more so since there is also the fine distinction of takouromenos, an amballados of less than usual intelligence.
The typical amballados is one who understands what is required of him & has the ability or perhaps even the obligation to deliver, but despite on pain of death refuses. He is frequently immolated along with his victims in these disasters of his own creation but will not acknowledge fault under any circumstances (assuming said amballados survives in order to acknowledge anything, of course).
Their motives are often a mystery, perhaps even to themselves. It has been suggested that if an amballados receives an instruction at gun point not to jump into a vat of acid from a source he does not want to be seen to obey, he would rather die in the vat than live in the knowledge of his obedience however forced.
Thus to get rid of an amballados , (an outcome highly to be desired) instruct them, firmly, to breathe.