Autonomy is the capacity to act on principles that are one's own and one will exercise this capacity by means of a process of rational reflection on these principles. Autonomy is thought to be necessary for attributing political responsibility.
However you look at it, in these books "power" tends to be an expression of the essential nature of the person or being whose power it is. On those occasions when we've seen Lord Foul act directly, he seems to exert the withering force of pure scorn. IMHO, that's pretty intense.