Frozen Soul

If you take this subclass your character has been effected by a source of magical cold. Your body adapted to that and gave you magical protection and deep understanding of shivering cold.

Frozen Magic

Sorcerer Lvl
1st	Armor of Agathys	Frost Fingers
3rd	Rime's Binding Ice	Snilloc's Snowball Swarm
5th	Slow	Elemental Weapon (cold)
7th	Fire Shield	Ice Storm
9th	Cone of Cold	Hold Monster

 

In addition you have resistance to Cold Damage.

Chilled to the bones

Starting at first level whenever you deal cold damage you can choose to make your target roll a constitution saving throw against your spell safe DC.
On a failure the targets speed is halved and dexterity saves are made at a disadvantage until the end of your next turn. Creatures that are immune or resistant to cold damage are also immune to this effect.

You can use this feature a number of times equal to your proficiency bonus and regain all uses after finishing a short or long rest.

Freezer Burn

Your innate knowledge of the lowest of temperatures lets you instinctively flip the associated damage of fire based spells.

When you cast a spell that deals fire damage you can instead choose to deal cold damage. Spells cast in this way cannot ignite objects.

Creeping Cold

As a bonus action, you can lower the temperature in an 30-foot radius centred on a point you can see within 60 feet until the start if your next turn.
Within this area, all cold damage dealt to creatures is increased by your proficiency modifier, all saving throws to reduce cold damage are made with disadvantage, and all creatures have resistance to fire damage.

You can use this ability a number of times equal to your charisma modifier, minimum of one. You regain all uses of this feature upon completing a long rest.

Frozen Solid

If you deal Cold Damage to a creature suffering from the Chilled to the bones effect you can spend 2 Sorcery Points to make them roll a constitution saving throw against your spellsave DC or become Paralysed until the end of their next turn.