GeryonHuge fiend (devil)
Legendary Resistance (3/day). If Geryon fails a saving throw, he can choose to succeed instead.
Magic Resistance. Geryon has advantage on saving throws against spells and other magical effects.
Magic Weapons. Geryon’s weapon attacks are magical.
Regeneration. Geryon regains 20 health at the start of his turn. If he takes radiant damage, this trait doesn’t function at the start of his next turn. Geryon dies only if he starts his turn with 0 health and doesn’t regenerate.
Spellcasting. The geryon uses Divinity (Cha) to cast spells (spell save Difficulty 21, +13 to hit with spell attacks). It has 21 mana, a mana limit of 4, regains all expended mana when it finishes a long rest and regains half its total mana (rounded up) when it finishes a short rest. It knows the following spells:
1 mana: divine word
3 mana: symbol of death/pain
Claws. Melee Weapon Attack: +16 to hit, reach 3 m. Hit: 23 (4d6 + 9) slashing damage. If the target is Large or smaller, it is grappled (Difficulty 24) and is restrained until the grapple ends. Geryon can grapple one creature at a time. If the target is already grappled by Geryon, the target takes an extra 27 (6d8) slashing damage.
Stinger. Melee Weapon Attack: +16 to hit, reach 4 m. Hit: 14 (2d4 + 9) piercing damage, and the target must succeed on a Difficulty 21 Fortitude saving throw or take 13 (2d12) poison damage and become poisoned until it finishes a short or long rest. The target’s maximum health is reduced by an amount equal to half the poison damage it takes. If its maximum health drops to 0, it dies. This reduction lasts until the poisoned condition is removed.
Teleport (1/turn). Geryon magically teleports, along with any equipment he is wearing and carrying, up to 20 meters to an unoccupied space he can see.
Variant: Sound the Horn (1/long rest). Geryon blows his horn, which causes 5d4 minotaurs to appear in unoccupied spaces of his choice within 200 meters of him. The minotaurs roll initiative when they appear. They remain until they die or the Geryon dismiss any or all of them (no action required).
Legendary Actions (3)
Only one legendary option can be used at a time and only at the end of another creature’s turn. The geryon regains spent legendary actions at the start of its turn.
Infernal Glare. Geryon targets one creature he can see within 10 meters of him. If the target can see Geryon, the target must succeed on a Difficulty 21 Will saving throw or become frightened of Geryon until the end of its next turn.
Swift Sting. Geryon attacks with his stinger.
Teleport. Geryon uses his Teleport action.
On initiative count 20 (losing initiative ties), the geryon takes a lair action to cause one of the following effects; the same effect can’t be used two rounds in a row:
Geryon causes a blast of cold to burst from the ground at a point he can see within 20 meters of him. The cold fills a cube, 2 meters on each side, centered on that point. Each creature in that area must succeed on a Difficulty 21 Fortitude saving throw or take 28 (8d6) cold damage.
Geryon targets one creature he can see within 10 meters of him. The target must succeed on a Difficulty 21 Will saving throw or become restrained for 1 minute. The target can end the effect on itself if it deals any damage to one or more of its allies.
Geryon casts the banishment spell.
The region containing the geryon's lair is warped by the geryon’s magic, which creates one or more of the following effects:
Intelligent creatures within 2 kilometers of the lair frequently see shimmering portals leading to places they consider safe. Passing through a portal always deposits a traveler somewhere in Stygia.
Freezing strong winds howl around the area within 2 kilometers of the lair.
Howls and screams fill the air within 2 kilometers of the lair. Any creature that finishes a short or long rest in this area must succeed on a Difficulty 21 Will saving throw or derive no benefit from the rest.
If Geryon dies, these effects fade over the course of 1d10 days.
No concoctions, maneuvers, or spells
All creatures in this system should have maneuvers or spells. You should add some maneuvers or spells to this creature. If you do so, please make a suggestion on github so I can finish adding maneuvers and spells to all creatures via https://github.com/mlenser/kryx-rpg-issues/issues/9.