Where the Old Blood excelled was he charged out of the unit of Cold One Cav into his unit of Plague Monks with Plague Furnace and issued a challenge and single handed took down Furnace and rider in turn 2.
The rest of the Cold One Cav protected his flanks from a unit of Clan Rats, a unit of Slaves and a unit of Giant Rats with couple of Pack Masters and a Master Molder. They were awesome, first time I have had them last all six turns.
Having a mounted BSB in that unit made a HUGE difference, I will never run Cold One Cav without having the BSB in the unit or right next to the unit ever again.