Perhaps mastery is a better word, which is what the Tibetan word for Buddha, sangs rgyas, implies in certain contexts. In Tibetan there are countless words used to describe the state he achieved.
I used perfected because I think it ties in nicely with the Paramitas, "The Perfections" that must be cultivated in order to achieve the fully enlightened state.
These perfections include generosity, ethics, patience, effort, concentration which are the method side and wisdom, which is the wisdom side
Once enlightenment is achieved the two obscurations- afflictive obscurations and obscurations to omniscience, are completely cleared away.
Of course, I am in the Zen forum here so if my Mahayana Paramitayana ideas from being steeped in mostly Gelug and some Kagyu teachings diverge from the understanding in this section of the forum, I am the one who is out of my element so I apologize. I do think though that from the little I know of the Avatamsaka Sutra for example and the Perfections of wisdom Sutras, this should be a pretty general understanding.
Of course in the Gelug and Kagyu traditions this is definitely a recognition that the ´"perfect state" is within us, in terms of our Buddha-nature. But this is understood to be covered by the defilements. So the tradition of the Gelug especially is to emphasize the accumulation of the two collections of merit and wisdom through the six perfections, as well as the purification of the obscurations, so that that Buddha nature can be "activated". The presentation you find on this topic comes from the Sublime Continuum or Uttaratantra Shastra, which is an explanation of important teachings of Lord Buddha on Buddha Nature.
Anyways, just responding to the qualm but of course this is off topic and also in the wrong section of the forum!