Frozen Heart subclass

Legends tell of people that have been known for their cruelty on others. Their hearts reflect the personalities that they have inherently developed once they've aquired this magic, either by ritual, curse or other means. While there are those that keep their kind hearted nature, many of lost their spirit and are often dethatched, uncaring of others.

Frigid Soul

Propelled by a heart of ice, the blood in your veins runs cold. At 1st level, you’re naturally adapted to cold climates, as described in chapter 5 of the Dungeon Master’s Guide, and you can move across difficult terrain created by ice or snow without spending extra movement.

In addition, any spell you cast that deals damage, you can choose to deal cold damage instead (no action required). You also have resistance to cold damage.

Frozen Heart Quirks

Frost Skin

The arcane magic you command is infused with elemental ice. You can speak, read, and write Primodial. (Knowing this language allows you to understand and be understood by those who speak its dialects: Aquan, Auran, Ignan, and Terran)

As the magic flows through your body, you discover you can create layers of frost upon your skin. While you are not wearing armor or wielding a shield, your AC equals 10 + your Dexterity modifier + your Charisma modifier.

Origin Spells

Your Frozen Heart grants access to specific frost based spells at levels 1, 3, 5, 7, 9, and 11.

⁴You can only conjure ice-themed elementals using the spell in this subclass. Likewise you can any spells on this list in ice form

Gathering Frost

Starting at 6th level, whenever you deal cold damage to a creature with a spell of 1st level or greater, you can reduce its speed by half on its next turn.

The Coldness Closing In

Beginning at 6th level, you can use your action and spend 2 sorcery points to create a simple object or structure made of ice, such as a stairway, a sword, or a solid block. It must reside within a 10 foot cube centered on a point within 120 feet of you. If you attempt to freeze a creature, it must make a Strength or Dexterity saving throw (target's choice) against your spell save DC. On a failure, it is encased within the ice. The target can repeat the saving throw at the end of each of its turns, escaping the ice on a success.

Alternatively, using a bonus action you can turn areas of water to ice within a 40 foot cube centered on a point within 120 feet of you. You cannot freeze areas of water that would trap a creature in ice.

At 14th level, you can spend 2 additional sorcery points to form your creation out of True Ice instead.

• The Nature of Ice
  
  • The ice that you create is abnormally cold and dense, but it isn't magical. At room temperature, it melts at a rate of 1 foot every 8 hours. The DM may rule that environmental factors increase or decrease this rate.
  • Each 5 foot square section of ice has AC 10, 20 hit points, and vulnerability to fire damage. Reducing a frozen section to 0 hit points destroys it.
  • Creations made of True Ice are magically durable. They do not melt, and their sections have AC 20 and 40 hit points, no longer being vulnerable to fire.

Winter's Embrace

At 14th level, you gain Otiluke's Freezing Sphere as an available sorcerer spell to learn. Also, spells you cast ignore resistance to cold damage. When you cast a levelled spell that includes a cold damage roll, you gain temporary hit points equal to half your sorcerer level rounded down. This method also stacks temporary hitpoints with armor of agathys.

Additionally, you can use your action to encase yourself in a protective cocoon of ice for 1 minute or until you choose to end the effect at the end of your turn. You become petrified and gain temporary hit points equal to twice your sorcerer level at the start of your turns and this turn which last until the effect ends. You maintain awareness of your surroundings.

Once you encase yourself in this way, you can't do so again until you finish a long rest or consuming 5 sorcery points to use it again.

Eternal Winter

Beginning at 18th level, you can extend your icy grip across the land. Now having manifested the powers of winter comparable to deities there are few that can match the ferocity of your ice magic. As of now, you are immune to the effects of Cold and the magic relating to cold. The intensity of the frost also makes you able to withstand the heats of flames much more effectively than others, giving you fire resistance as a result.

As an action, you can create a block or object of true ice that fits in a 10x10 ft cube without spending sorcery points. In addition, instead of being able to trap only one creature at a time, you may now trap hostile creatures within a 10 foot radius in a block of true ice, rolling a con save based on your spell save modifier or take 4d8 damage and be restrained until the start of it's next turn

As an action, you can spend 5 sorcery points to exude a freezing aura to a distance of 20 feet. For 10 minutes or until you lose your concentration (as if you were concentrating on a spell), surfaces within the aura become coated in true frost, water freezes instantly, and you take on the appearance of a minor god or goddess of winter. A hostile creature that starts its turn within the aura must succeed on a Constitution saving throw or take 3d8 cold damage and become restrained until the start of its next turn. A creature that succeeds on this saving throw is immune to this effect for the next 24 hours. At the beginning of your turn, you can expand or reduce the range of the aura by 10 feet, to a maximum of 100 feet.

Credit to Hesbravelwt for the original concept of this class, I loved the concept of the class so I made my own small tweaks as a first-time subclass