Nighthaunt player here with a question:
I just finished a game against DoT army, which wiped the floor with me. If I recall correctly it looked like this:
Hosts Duplicitous
Kairos
Lord of Change
2x Exalted Flamers
2x 10 Tzaangors
2x 10 Pink Horrors
Burning Sigil of Tzeentch
Battleplan was Power in Numbers.
The whole army was placed in the center of the deployment zone as a bubble. I was told beforehand that Tzaangors will use Ornate Totems with 4 dice each in the hero phase*, because there were four wizards nearby. So I stayed out of 18" range in the first round, but tried to flank the army via Vanishing Phantasms / deepstrike. That worked out, but afterwards 2x 20 nearby Bladegheist Revenants were deleted by mortal wounds. When my Grimghast Reapers arrived in the third turn without general (who was easily killed by Kairos) the two big chickens just picked apart my remaining models. Just my Chainrasp blob stayed intact in my deployment zone.
I don't know how to engage this army next time with all my melee units. Kairos and the Lord of Change are out of reach and the Tzaangors in the flanks get revived and dish out mortal wounds to everybody. I can't retreat either, which shuts down charges for Wave of Terror.
*edit: He did it to every enemy unit within 18" though.