Old King Heus

Today’s entry is once again inspired by the OGL cantrips I released some time ago. This time, I am attempting to hit a legendary creature with a lair around Challenge 8. If you have seen my previous attempts, or looked at printed creatures like the Aboleth, Solar, and Tarrasque, you know it’s something of an art to creature a legendary creature and a lair to feature, while still hitting the expected Challenge. I think I am getting a feel for it, but I might be wrong. As always, I’ll go over the design notes at the end. Today’s creature is taken from the piercing wail cantrip.

Dread of the Ancient Elves

The text for piercing wail is a journal entry of a man exploring an ancient ruin with his sister. The Ruins of Hersenkas are presented as an island castle in an ancient valley, and was once the home of King Heus. The story also mentions Anam and Abhainn, twin deities of luck and travel, responsible for fate and misfortune in equal measure. The text also heavily implies the sister became a banshee while her cowardly brother fled in terror. Wrap this all in a bow, and you get a very celtic/welsh-inspired tale, which puts me in mind of some ripe fey and elf story.

In my mind, King Heus once ruled the kingdom of Hersenkas hand-in-hand with his sister, the Queen With No Name. They each had their own consorts, but only twins rose to the throne in this land, which saw itself as almost a religious oligarchy on behalf of Anam and Abhainn. There was some tragedy, likely fey related, and the Queen disappeared or became a terrible banshee while King Heus died from despair, yet never left his throne, forever awaiting the return of his sister. Those who enter the ruins are meant to forever join his spectral court he holds in her honor. King Heus is also a large creature, as I wanted to convey a larger-than-life fairy tale/folk tale nature to the entire endeavor.

The Ruins of Hersenkas

The Ruins of Hersenkas lies in the center of mist-covered Loch Bheannaigh, in the long isolated Ghrian Pog valley. Hersenkas was once a magnificent castle of opalescent stones and towering spires, with parapets portraying dragons and griffons in flight. Once a place of light, justice, and festivities, the ruins have become a place of lingering night, fear, and horrific visions. No one is certain what exists in the ruins, as each tale of those returning are invariably different, save for the accounts of Old King Heus.

Adventurers might seek out the Ruins of Hersenkas on a quest from an Archfey, to acquire weapons of great power, the swords Moralltach and Beagalltach or the spears Gae Buide and Gae Derg would be appropriate from a mythology standpoint, to rescue those kidnapped as superstitious sacrifices, or to discover ancient cultural artifacts, such as the lyre of the last dance. It could also simply be a side story or main thrust of a low to mid-level campaign. Again, the intent is that these are fluid enough that they can work in a campaign with very little alteration needed. Feel free to change the names to whatever is appropriate.

Lair Actions

When fighting in its lair, Old King Heus can invoke the magic of the Ruins of Hersenkas to take lair actions. On initiative count 20 (losing initiative ties), Old King Heus takes a lair action to cause one of the following effects:

• Old King Heus can cause the keening wail of the banshees to echo up and down the halls of the ruins. All non-undead creatures within the Ruins of Hersenkas must succeed on a DC 15 Wisdom saving throw or become frightened. This condition lasts until the creature is no longer in the Ruins of Hersenkas. The creature may make a new saving throw with disadvantage against the frightened condition at the end of each of its turns. Once a creature has succeeded on this saving throw, it is immune to this feature for the next 24 hours. Old King Heus may not use this lair action again until he has used a different one.
• Moonlight strengthens the attacks of undead within the Ruins of Hersenkas. All undead weapons count as magical silver weapons for purposes of overcoming damage immunity and resistances, and successful weapon attacks made by undead within moonlight deal an additional 4 (1d8) psychic damage. While maintaining concentration on this effect, Old King Heus can’t take other lair actions.
• The Ruins of Hersenkas prey on the fears of those who venture into it. Old King Heus can cast phantasmal killer on any creatures he can see that are within 15 feet of any mirrors, painting, pottery, or statuary within the Ruins of Hersenkas. While maintaining concentration on this effect, Old King Heus can’t take other lair actions. Old King Heus may not use this lair action again until he has used a different one.

Regional Effects

The Ruins of Hersenkas is an entryway to the feywild and the shadowfell, alternating rule by day and night. This alters the surrounding environs in the following ways:

• Mist lightly obscures the area within 1 mile of the Ruins of Hersenkas during the day light. This mist causes light distortion at night, causing all Intelligence (Investigation) and Wisdom (Perception) checks to be made with disadvantage.
• Iron becomes uncomfortable to wear and wield within 1 mile of the Ruins of Hersenkas. Wearing iron armor causes all Dexterity ability and exhaustion checks to be made with disadvantage, and all attacks made with an iron weapon are made with disadvantage.
• As an action, Old King Heus can prey upon the personality, bonds, flaws, and ideals of those within 1 mile of the Ruins of Hersenkas. Old King Heus creates scenes from a creature’s background as if he had cast major illusion as a 6th-level spell slot. Old King Heus may create any number of objects to make the scene as real as possible, but may only focus on one creature at a time.

Design Notes

Old King Heus is based on the death knight, though scaled way down and with much of the spellcasting element removed. The abilities he has in their place are mental in nature, and draw in equal measure upon psychic horror and terrible attraction. From a Planescape perspective, it also draws upon some themes of the Astral Plane, which would be appropriate from a “dead power” sort of view point.

I wanted loss of his sister to play a central role in his overall theme, and tying that into a charm power seemed like the right call, especially since this is meant to be an elven and fey-type encounter. It is also a greater setup for banshees and ghosts, which should play a large role in the overall dungeon of the Ruins of Hersenkas itself. Having multiple stories and quests you can resolve without conflict, and likely through exploration and social interaction with OTHER banshees and ghosts is about right on the money for what I had in mind here. Of course, you’d end up fighting some, and having weird fey creatures, like fey hounds in the kennels, would be a great addition.

The three big abilities in the encounter and the lair are those most easily overcome by immunities and features that give characters advantage against them. While the charm ability specifically strips immunity, none of the other abilities do. I am attempting to convey a greater fey presence behind the situation here, thus a sort of ultra-charm makes sense, to me. The disease acts as a nice timer for the fight, allowing quite some time before it become a concern, but it’s something you need to keep an eye on nonetheless.

I don’t think any of the abilities here are big party-wipe abilities, which is intentional for the Challenge. If you add other undead to fill out the court, which is what I would recommend, I think the encounter becomes a lot more well-rounded. It can definitely stand as a solo encounter, particularly if you are managing the lair effects well, but having it be more of a courtly encounter that spills into a nightmare come to life type of scenario feels right, to me.