By Alan McCoy from Dungeons & Dragons: Fundamentals
How to build challenging
encounters against a Bone Devil.
This has been prepared using 5E core rules. It assumes that you are on the prime material plane.
General Information:
For a DM, fighting as a Devil is tricky, these highly intelligent, highly motivated fiends will never be found on the prime material plane without a purpose. Unlike Demons, who when granted access to the world will seek to cause as much strife and mayhem as possible, the Bone Devil will be bound by the orders of the those above it in the Diabolical chain of command and by the terms laid on them by the agreement made with their Summoner.
The Hells have a strict chain of command, everyone from the Arch-Devils to the lowliest Lemure has a place upon the chain, succeed and you will gain power and move up the chain. Fail and you will be cast down.
The encounter will always be dictated by the answer to the question: “What are your Orders?”
If you encounter a devil in the hells, the encounter will be far more dangerous as you are now on its home territory, thus it is only subject to the diabolical chain of command and whatever orders they have issued.
In most situations: One of Hell’s standing Orders is to test anyone who summons a Devil, slay them and return to Hell with the soul of the summoner.
Those daring to summon one of these fiends will find their summoning circle challenged, the fiend either trying to get in, or to get out. If and only if the summoner survives this challenge, the Devil will be bound to take the orders of the summoner.
Consider this scenario: A Warlock with a Fiend Patron has decided that he has had enough of the parties meddling. He summons a powerful Devil to act as an Assassin to eliminate the party.
What are your Orders? — “To kill Character A, Character B, and Character C, then return to the Hells.”: The Devil will then be legally allowed to act aggressively as needed to carry out those orders. It may have other orders from the Diabolical chain of command as well, woe to any summoner leaving loopholes.
The Bone Devil or Osyluth
As stated earlier, the Hells have a strict chain of command which is dictated by hierarchy and rank. Every devil passes upward through every rank as they progress. The Bone Devil is the most powerful of the group generally termed ‘Lesser Devils’ and of course they are ambitious and eager to gain power and the status of Greater Devil.
Bone devils are driven by hate, lust and envy, they are the cruel taskmasters of the Hells and they are responsible for putting those devils under their orders to work. They demand and are accustomed to, rapid obedience from subordinates.
Let’s review what we know of the Bone Devil:
Appearance: A bone devil looks like a humanoid husk with dried skin stretched tight across its skeletal frame. It has a skull like head and a segmented scorpion like tail. They can and often do display insect like wings. The wings are used to make them even more impressive to mortals, they are not necessary for flight. The Bone devil can be found either unarmed and fighting with its impressive claws or armed with a hooked polearm. A horrible stench of decay hangs in the air around them.
Senses: Darkvision 120 feet, enhanced by Devil’s Sight: They can see even in magical darkness. Passive Perception: 12. Active Perception: +8 or more. Since the fiend has Telepathy, it can detect you from your thoughts.
Defenses: AC 19; HALF DAMAGE FROM: Cold; Bludgeoning, Piercing and Slashing attacks unless magical or Silvered. (Damage Resistance); Immune to Fire or Poison Damage. Immune to the Poisoned Condition; Magic Resistance: Advantage on Saving Throws vs Spells and other Magical Effects.
Saving Throws: Int +5, Wis +6, Cha+7
Str: 18(+4); Dex: 16(+3); Con: 18(+4);
Int: 13(+1); Wis: 14(+2); Cha: 16(+3)
Move: 40 ft; FLY 40′
Communication: Telepathy 120-foot range; Speaks Infernal. Skill: Deception +7; Insight +6
In combat, the Bone Devil has the ability to Multi-Attack with Claw/Claw/Sting or if under orders or choses to subdue in the event of further orders, it can produce and fight with a hooked polearm (which can grapple) while it uses its tail to sting.
Finally, once each day the fiend can summon other devils to its aid (40% chance on the prime material, 100% in hell): Either another bone devil or 2d6 spined devils.
Now that we know what it can do, and remembering the catchphrase “What are my Orders”, let’s consider possible Strategies:
As a Lesser Devil, the boned devil has not yet earned much magical ability. It is primarily a heavy combatant with one exception: It can fly! This brings the combat into three dimensions and makes it far more dangerous. Remember that with flight, it can utilize its full move forward, back, up or down. Difficult terrain is for the landbound.
Since the fiend’s claws have a reach of 10 feet, as does its tail sting, the fiend does not have to close into the melee range of those it is attacking. It can fly up twenty to thirty feet, then utilize its movement to swoop down to attack at ten-foot range, then return to altitude. Opportunity attacks are useless unless an attacker has a combat range of at least ten feet.
The fiend has magic resistance (thus advantage to saves) against magic and magical effects; and damage resistance to non-silvered piercing weaponry.
While hovering, the boned devil, provided its orders allow it to do so, might attempt to bargain telepathically. They are great liars but will be bound by the terms of any contract. Despite the legend, a signed contract isn’t necessary, merely the agreement of the soul in question.
If the Devil believes that it is within its orders, while skyborne it will immediately attempt to summon a flight of spined devils to aid it. Armed with their pitchforks, these flying fiends will usually use their flaming tail spikes to attack from range. (two per round) While they don’t have the reach of their bone devil master, they do have the ‘FLYBY’ ability, thus they do not provoke opportunity attacks.
While a bone devil can summon another bone devil, it is usually very reluctant to do so unless its orders require it. A technical equal, the bone devil would have to share the spoils with the summoned devil.
A bone devil who accomplishes its mission will either leave, or it will harvest the souls of the dead for the hells.