Homebrew Arch Devil Species Details

Devils personify tyranny, with a totalitarian society dedicated to the domination of mortal life. The shadow of the Nine Hells of Baator extends far across the multiverse, and Asmodeus, the dark lord of Nessus, strives to subjugate the cosmos to satisfy his thirst for power. To do so, he must continually expand his infernal
,armies, sending his servants to the mortal realm to corrupt the souls from which new devils are spawned.
Lords of Tyranny.

Devils live to conquer, enslave,
and oppress. They take perverse delight in exercising authority over the weak, and any creature that defies the authority of a devil faces swift and cruel punishment. Every interaction is an opportunity for a devil to display its power, and all devils have a keen understanding of how to use and abuse their power.
Devils understand the failings that plague intelligent mortals, and they use that knowledge to lead mortals into temptation and darkness, turning creatures into slaves to their own corruption. Devils on the Material Plane use their influence to manipulate humanoid rulers, whispering evil thoughts, fomenting paranoia, and eventually driving them to tyrannical actions.
Obedience and Ambition.

In accordance with their lawful alignment, devils obey even when they envy or dislike their superiors, knowing that their obedience will be rewarded. The hierarchy of the Nine Hells depends on this unswerving loyalty, without which that fiendish plane would become as anarchic as the Abyss.
At the same time, it is in the nature of devils to scheme, creating in some a desire to rule that eclipses their contentment to be ruled. This singular ambition
is strongest among the archdevils whom Asmodeus appoints to rule the nine layers of the Nine Hells. These high-ranking fiends are the only devils to ever sample true power, which they crave like the sweetest ambrosia.

Arch Devil Traits

Damage Resistances cold; bludgeoning, piercing, and slashing from nonmagical weapons that aren't silvered.

Devil's Sight.

Magical darkness doesn't impede the devil's darkvision.

Magic Resistance.

The devil has advantage on saving throws against spells and other magical effects

Damage immunities

Fire, poison 

Darkvision

Can see 120ft in darkness but only in shades of gray.

Condition immunities

Poisoned 

Damage resistances

cold; bludgeoning, piercing, and slashing
from nonmagical weapons that aren't silvered

Language

You know Infernal, Abyssal, and two languages of your choice.

Flight

If the character has wings it has a flying speed of 50ft

Torturer

You have a weapon proficiency in either a glaive and whip, or a halberd and whip. You also get the proficiency in the poisoners kit.