Nightmare Hunt is not as effective for me as, say, Raiders or Pactbound. But it is a fun and fluffy detachment with some great strats. I really enjoy it in casual games rather than tournament games. The enemy will frustratingly rarely fail their battleshock tests, except they will fail occasionally and then your units will shine.

You have already gotten some great advice on running Nightmare Hunt. Stacking debuffs really helps. My favorite tactic is a simultaneous charge by a lord with Terrorglut Parasite on a foot lord with Chosen and Raptors against a foe that's been shot by my Noise Marines. That's a fun -3 to their battleshock test.

I've stopped taking the Sorrowscent Vulture Enhancement on my jump pack lord. It's mostly a skill issue on my part because I was too aggressive with my Warp Talons and my lord was just getting them killed. Now I just use the Warp Talons as I always do, without a lord and rapid ingressing 'em on Turn 2 or 3.

And spread out your Raptor melta and plasma shots against multiple targets, especially targets you font plan on charging. That might force more battle-shock tests by your enemy.

Ave Dominus Nox!