A look at the Warscrolls and units within the Ossiarch Bonereapers.
"Relentless discipline points are used like command points, but only for command abilities found on Ossiarch Bonereapers warscrolls. Representing the tactical diversity of the Ossiarch Legions, many units have their own command abilities in the same manner Heroes do. Kavalos Deathriders, for example, can form up to make deadly charges capable of scything through units before blows have been struck."
"The Gothizzar Harvester, for instance, can recycle fallen units (both friend and foe) to make new ones. Indeed, Katakros himself changes as he takes wounds, starting as a contemptuous commander capable of drawing on the powers of several retainers and ending up as a brutal combatant in his own right. He’s not so much a Hero as a mini-boss fight for your enemies!"