My local game store is having a mercenaries league where we have to use 150 points of mercenaries for our army's. They do not take up a force org slot and can be anything you can think of here is an example (courtesy of pyrain)

Klaralak, Herald of Fury

A lost daemon of a long-dead God, Klaralak whispers secrets of summoning to those in need. Just a little blood in his name, what does it matter, amidst a battlefield choked with death? Who will ever notice a few wounded missing? Once released, he preys on the weak, vulnerable, and/or wounded, flitting away from stand-up fights to tear into support units or fleeing troops.

150 points for Klaralak and 4 Chaos Furies. Up to 5 additional furies can be added to the unit at +15 points each.

...........WS..BS..S...T...W...I...A...Ld..Sv
Klaralak:..5...0...5...4...2...5...4...10..5+ invulnerable
Fury:......3...0...4...4...1...3...2...10..5+ invulnerable


Unit Type:
Jump Infantry

Special Rules:
All: Count as Daemons, Fearless, Can and Must Always Deep-Strike, the unit has Hit&Run as long as Klaralak remains in play
Klaralak: Rending