Rime Heart Sorcery

When your power first appeared it was much like most sorcerer's, maybe you accidentally breathed out a spike of ice, or maybe you caused a freak snow day, all that can be said was that you were different. Your affinity for the cold can be from many things, nearly dying in a blizzard, sheer fascination with the cold, or maybe you can trace your lineage back to a being from the Frostfell. However it happened, the power of winter’s bite is at your fingertips.

Wintry Veins

Being infused with the chilling power of ice and snow, you naturally have resistance to Cold damage at 1st level. Additionally, your icy blood allows you to be able to survive in Arctic temperatures without protections.

Along with this boon, you can channel that extra ice to deal Cold damage equal to your Charisma modifier when you cast a spell that deals Cold Damage.

Deep Cold

There’s cold, and then there’s cold, and you have both at your fingertips. At 6th level when you damage a creature that is normally resistant to Cold Damage with a spell that deals Cold damage, you ignore that resistance. If a creature has immunity to Cold Damage, you may spend 2 sorcery points to treat that immunity as resistance (this will not make the creature take full damage, but instead the usual half).

Cold Snap

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

Alternatively, you can spend 3 Sorcery Points to instead encase the damaged creature(s) in ice. The affected creatures are treated as paralyzed. You may dismiss and melt the ice in whole or parts (i.e., thawing the ice around a creatures head but leaving its body encased).

Chill to the Bone

Beginning at 14th level, you’ve learned how to command the power of Cold from even within others. You can target one creature without immunity to Cold damage within 60 feet, and force it to make a Constitution saving through against your spell save DC. If that creature fails, it becomes frozen (treated as the petrification status) from the inside out. On a successful save, the creature instead takes 5d10 of Cold Damage. You may spend up to 5 sorcery points to increase the save DC by 1 per point spent. This ability can be used a number of times equal to your Charisma modifier per short rest.

Deep Freeze

At 18th level, you have fully become one with the ice spread throughout your body and soul, and you can ‘share’ this frigid power with others. As an action on your turn, you can spend 5 Sorcery Points to freeze everything around you in a 60ft radius sphere. All hostile creatures within this area must make a Constitution Saving Throw or take 7d10 Cold damage, or half as much on a successful save. Creatures that fail the save must make another Constitution as the chill slowly crawls through them, dealing 4d10 Cold damage. If they fail both saving throws, at the end of their next turn they must make a final saving throw, or be frozen solid, killing them. You may spend two sorcery points to give a creature disadvantage on each of these saving throws. This feature is usable once per long rest.