So, as far as droppin' the D goes, a properly equipped Transcendent C'Tan seems nearly as good as a Revenant.
If you buy Transliminal Leap and Withering wave, you can
- make an 18" move. Anything you pass through takes a D hit
- shoot a hellstorm template (like a flamer template but 16" long and 5" wide at its widest), and everything underneath it takes a D hit.
- Also shoot another weapon somewhere else, for example, a 10" blast strength 9 AP 2 gun, or another Hellstorm template which is str 6 AP2.
If the C'Tan starts in the middle of the table and goes first, I could easily see it killing its points (about 800) on the alpha strike. The fat end of the template would be able to reach anywhere on the table except for the very corners.