The Frozen One

Your patron is a powerful entity born or buried deep within the frozen wastes. This being's motives are often as slow-moving as a glacier and have a timeline based on ages. Generally, they plot for revenge, release, or rule. Beings like this include Levistus, the frozen Archdevil; Geryon, the hunter of Stygia; Cryonax, the archoelemental of the Frostfell; Albrathanilar, the eldest white dragon; or an archfey like the Prince of Frost.

Expanded Spell List

The Frozen One lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Frozen One Expanded Spells

SPELL LEVEL	SPELLS
1st	ice knife, absorb elements
2nd	snilloc's snowball swarm, warding wind
3rd	sleet storm, slow
4th	fire shield, ice storm
5th	cone of cold, control winds

Bonus Cantrip

You learn the ray of frost cantrip. This counts as warlock cantrips for you, but it doesn't count against your number of cantrips known.

Creeping Cold

The essence of your patron seeps into your spells. Whenever you successfully make an attack roll or force a saving throw that deals cold damage to a creature, their speed is reduced by 10 feet until your next turn. If a creature's speed reaches 0 or already is 0 when this effect takes place, they are restrained as well until your next turn. If you deal cold damage multiple times in a turn, each time reduces the target's speed.

You can further tap into your patron's essence as a bonus action on your turn, causing your cantrips to deal an extra 2 points of cold damage. The damage increases when you reach certain levels in this class, increasing to 3 at 5th level, 4 at 10th level, 5 at 15th level, and 6 at 20th level.

Heart of Ice

Starting at 6th level, your link to the cold allows you to become more resilient and potent in working with it. You gain resistance to cold damage and are unaffected by the negative effects of being in a cold environment. Nonmagical ice and snow also do not count as difficult terrain for you and you can move across them with ease.

At the beginning of your turn, you may choose to lose your resistance to cold to allow your attacks and spells to bypass creatures' resistances to the elements. You lose resistance to cold damage for the round. Doing so causes your attacks and spells ignore resistance to cold damage on your turn, and creatures that have immunity to cold become resistant for you instead. 

Rime Field

Starting at 10th level, the bitter cold essence of your patron bleeds into the area around you. The area within 5 feet of you becomes covered in a slick sheet of ice as you walk around. The area around you is considered difficult terrain for all creatures apart from yourself.

As a reaction to a creature entering or leaving this ring of ice, you can harden the ice around the creature, forcing it to make a Constitution saving throw against your warlock spell save DC. On a failed save, the creature is encased in ice. They take cold damage equal to your warlock level and their movement speed becomes 0 until the end of your next turn. On a successful save, the creature continues, uninterrupted. Once you use this part of this feature, you cannot use it again until you finish a short or long rest.

Frozen Bastion

As an action, you cause up to four pillars of ice to burst from places on the ground that you can see within 60 feet. Each pillar is a cylinder that has a diameter of 10 feet and a height of up to 30 feet. The ground where a pillar appears must be wide enough for its diameter, and you can target the ground under a creature if that creature is Large or smaller. The area within 5 feet of each of the pillars is filled with frigid air. Each creature entering or starting its turn in the area must make a Constitution saving throw. That creature takes 2d8 cold damage for each pillar they are near on a failed save, or half as much damage on a successful one. You are immune to this effect and can choose a number of creatures equal to your Charisma modifier to be immune as well.

Each pillar has AC 12 and 30 hit points and is vulnerable to fire. When reduced to 0 hit points, a pillar shatters and is destroyed.

If a pillar is created under a creature, that creature must succeed on a Dexterity saving throw or be lifted by the pillar. A creature can choose to fail the save.

If a pillar is prevented from reaching its full height because of a ceiling or other obstacle, a creature on the pillar takes 4d6 bludgeoning damage and 4d6 cold damage and is restrained, pinched between the pillar and the obstacle. The restrained creature can use an action to make a Strength or Dexterity check (the creature’s choice) against your spell save DC. On a success, the creature is no longer restrained and must either move off the pillar or fall off it.

Once you use this feature, you cannot use it again until you complete a long rest.