Roof, I think 9d parses as a type of vermin folloewing hidden instruction in the clue, followed by ‘heart of satan’ and 3-letter ‘get’ - no W left on. It’s own!
A fierce one today, I made v slow progress (my excuse is that I’ve finally succumbed with my first positive Covid test on Friday, although it just feels like a bad cold). Got stuck several times and picked it up again after breaks and Everyman. Completely stuck with the SE corner until ,someone here talked about a ‘24A moment’ and the last few fell into place.
Thanks Paul, and thanks to all here