Anyone the Norscans don´t kill in their raids are captured, destined for one of three fates. Many are sacrificed to their dark Gods in horrible ways. At least death is quick for those souls. Others are sent to the slave markets of Norsca, to toil as a slave for the rest of their miserable lives. And then there are the ones that the Norscan´s deem as more worthy. Those that have fought hard in combat. These few men are put to work as gladiators, forced to fight their comrades in battles to the death for the amusement of the Norscan barbarians.
The gladiators are strapped to demonic weapons, weapons that consume the mind and soul of their carriers. What were once the best men of the Empire are turned into bloodthirsty savages. With their mind and humanity lost to the daemons, the most brutal and ruthless of the gladiators earn the right to fight in the vanguard of the Norscan raids. Men of the Empire no more, they charge into their former comrades without compassion and with no fear of death.
I converted up a troop of Reavers from a unit of Khador doom reavers. It was a fairly easy conversion, just snipping off their heads and swapping on some chaos warrior heads. I took inspiration from my Hellcannon and used the same demonic orange colors to make their blades seem like demonic weapons.
Reavers in kings of war are an interesting unit. A berserker type unit, they have the trademark fearless high nerve and a ton of attacks. However, reavers also come with speed 6, which is a lot better than usual speed 5 of infantry, and TC2 AND vicious, which makes them super dangerous.
When it comes to killing power for your points, a troop of these guys are in the top 2, competing with sons of Korgan troops with great weapons (sons are better vs DEF5+ unless reavers get bane chant). Of course, that is theoretical. You have to actually survive until you can get in combat, and you have to get a non-hindered charge with TC still intact. Those are a lot of IF´s, but if you get in, you average:
Vs DEF 4+ : 10 wounds
Vs DEF 5+: 7 wounds
Vs DEF 6+: 6 wounds
Throw in bane chant, maybe a skull pole for brutal, and a troop is a serious threat to most elite units. Get a flank and watch pretty much any unit disappear in a mist of choppy death.
Shooting and terrain is their natural enemies, so using them as a second line unit, for example behind bloodsworn is probably a good option. For survivability, Griffon banner is an interesting option in lists with multiple reaver units.
Unlike most troop style units, several items can actually be worth it, since the reavers hit far above their pay-grade. Macwars potion, if not used elsewhere, can possibly be worth it, allowing them to use terrain as cover and to remove hindered for most charges. +1 speed or +1 to charge are also interesting.