Naraak is massive, even for a Nagaji, their frame wider and taller than most mortals who ever set foot in Niswan, and every inch of it clad in gold. Their greeting to guests and challenge to foes begins the same way, every time: "I serve two masters: Phasanaash with my body, and Diomazul with my soul. Insult me, or either of them, and I will leave no trace that you ever lived." Phasanaash is a spirit naga exiled from her Tian homeland, having become quite wealthy running an import business in Jalmeray's greatest city, and Naraak is her most favored bodyguard, kept around for his devotion - and increasingly, as a lucky charm.
I think the ideal build for Naraak here is some mix of a Tyrant or hypothetical Lawful Neutral subclass for Champions and a Barbarian (ideally a fiendish one!), to represent that iron-willed warrior with an unholy rage within. I have a soft spot for weird, martial LE divinities like Diomazul and General Susumu, so this angle's too fun to pass up.