When the great demon prince Fraz-Urb'luu was imprisoned on the Material Plane by the mad archmage Zagig Yragerne, several opportunistic demon lords flocked to his abandoned layer, Hollow's Heart, hoping to make it their own. The ambitious minor demon lord Baltazo, a retired general with several Blood War victories under his ever-expanding belt, knew he could not hope to command Hollow's Heart, but he saw opportunity in the growing conflict. Instead of staking his own claim, he instead conquered the iron fortress of Shullen-Gat, on the precipice of the pit leading to Fraz-Urb'luu's lair. Commanding this gateway allowed him to subtly influence the affairs on the layer, affording him prestige elsewhere in the Abyss.

Upon Fraz-Urb'luu's return, the Prince of Deception wiped out most of the rival demon lords squabbling over his layer, but he saw value in a strong defense of the Pazunia gate. The two demons came to an agreement, and Baltazo now stands sentinel over the pit to Hollow's Heart as a sponsored vassal of Fraz-Urb'luu, for whom he sometimes acts as a diplomat or interlocutor.

Baltazo appears as an extremely corpulent human man with an elongated face and deep green skin that constantly fizzles and pops, spilling a variety of sickly fluids upon a poor-fitting military uniform festooned with dozens of ostentatious medals and ribbons.