Infernal War Machines are the tanks of the Blood War, and devils use them to fight demons and move about the hellscape. After the massive battles of the Blood War, other denizens of Avernus scavenge these wrecked machines for parts to make their own personalized war machines.
Polukranos represents the ideal hydra, a beast of such size and strength that the gods Nylea and Heliod both used their power to bind the monsters deep within the Nessian Forest where it dwells, growing and devouring all who wander into its territory.
Orcus is the Demon Prince of Undeath, known as the Blood Lord. He takes some pleasure in the sufferings of the living, but far prefers the company and service of the undead. His desire is to see all life quenched and the multiverse transformed into a vast necropolis populated solely by undead creatures under his command.