Screamerstar

The screamerstar is a Warhammer 40,000 tactic using Chaos Daemons. When used right it can be a devastating move (and a major annoyance) to the enemy player. Basically you take some heralds of Tzeentch on discs, roll on divination and try to get forewarning. also you need the grimoire of true names and it is strongly recommended to take fateweaver due to his reroll ability. once you have a herald with forewarning you cast it on a unit of Screamers (usually 6-9) and grant them a 4+ invulnerable save. you then proceed to use the grimoire and bringing them to a 2++. since they are tzeentch units they reroll saving throws of 1, giving you a crazy death star that can nearly not be killed. (keep in mind the herald on the disc can still be killed, so remember to roll for look out sir! and do not keep him in the front of the unit).