Below you'll find my WIP Vengeance prow alternative. I based her off of the Repulsive's prow with some modifications. She's .75 inches wide at her base, .5 inches wide at the top, and .25 inches deep. I built out a framework on Monday, filled her in with putty on Tuesday, and then with a hobby knife I trimmed the excess out and sanded it down to get my dagger shape when I got home tonight (the alternative was to repeat my hour of playing with obscure angles and plasticard lengths from Monday, which honestly, was not getting me anywhere. At all.) So far tonight, I've started adding the trim (so you can actually see her lines), and shaped the spine that I'll be using as a guide on the top to get that acute sloping Chaos prow effect.
1) build up the upper surface of the prow to a pointed edge;
2) start on the superstructure beneath the prow (bring it down similar to the Vengeance and Repulsive prows, add a couple of close defense turrets, bring the keel slightly forward onto it)
3) upper deck trim work (Chaos star), drill and mount antennae and sensor probes, add some gribbly squares and bits similar to Imperial ship prows to help hybridize the design
4) fill in that square gap between the prow and the hull, add some plating, and gribbly it up so it looks legit.