I find this a good read including the text he linked. https://app.box.com/s/jarnprcugpon7fzdj5xt8hif0c6i49y4

https://www.dharmawheel.net/viewtopic.php?f=39&t=36909&p=588086#p588086

Astus:

The suttas are quite clear on the matter that consciousness is one of the aggregates and it is very much impermanent. SN 12.64 itself states that "for the nutriment consciousness, if there is no delight, if there is no craving, consciousness does not become established there and come to growth." (Bhikkhu Bodhi translation), that is, there is no consciousness to talk about without nutriment. On the concept of unestablished consciousness mentioned there, see e.g. What the Nikāyas Say and Do not Say about Nibbāna by Bhikkhu Brahmāli, p 47ff.

Also, regarding consciousness, see chapter 4 of Theravada Abhidharma by Y. Karunadasa:

"Early Buddhism recognizes three basic psychological principles. The first is the dependent arising of consciousness, expressed in the well-known saying: “Apart from conditions, there is no arising of consciousness.” (M. I, 256: Aññatra paccayā natthi viññāṇassa sambhavo.) Consciousness is not some kind of potentiality residing in the heart and becoming actualized on different occasions. Nor is it a static entity that runs along and wanders without undergoing any change, a kind of permanent soul entity that transmigrates from birth to birth. (M. I, 256)"

And chapter 5:

"In the Abhidhamma psychology, bare consciousness, that which constitutes the knowing or awareness of an object, is called citta. It can never arise in its true separate condition. It always arises in immediate conjunction with mental factors, the factors that perform more specialized tasks in the act of cognition. In the books of the Abhidhamma Piṭaka the individual nature of consciousness is often sought to be described by positioning it in relation to other basic factors (dhamma) into which individual existence is analyzed.
...
As a basic factor of actuality (dhamma), consciousness is the mere occurrence due to conditions. (VsmṬ. 462: Yathāpaccayaṃ hi pavattimattam etaṃ sabhāvadhammo. See also Abhvk. 116; VśmS. V, 132.) It is not an entity but an activity, an activity without an actor behind it. The point being emphasized is that there is no conscious subject behind consciousness."

For Karunadasa on the subject of nirvana see chapter 10 of Early Buddhist Teachings: The Middle Position in Theory and Practice.