Iceborn

Your icey powers are linked to shards of ancient ice long forgot. Your bloodline is linked to this ice. Maybe your ancestors lived near the ice. Your family could have created the shard long ago or have a small piece of the ice within them.

Frozen Soul

You have a deep connection with the magics long lost, exemplified in your control over ice. You can speak, read and write Primordial. Additionally, you suffer no penalties for walking on ice or snow and are adapted to live in snowy, cold, climates. Aswell as that, you can now access all spells that deal cold damage. You can learn them as if they were sorcerer spells, and they count as sorcerer spells for the purposes of all effects.

Icey Companion

Also at 1st level, you learn the Find Familiar spell and it counts as a sorcerer spell for the purposes of all effects. You have the same restrictions of the spell when you use it, except your familiar is made out of ice, and becomes a construct instead of a fey, fiend or celestial.

Shivering Defense

Starting at 6th level, you gain resistance to cold damage. Whenever you cast a spell that deals cold damage, add your Charisma modifier to that damage. Additionally, you can cast Armor of Agathys once per long rest.

Shards of the Ancient Ice

At 14th level, the ice energy you channel through your magic manifests itself in combat. When you are hit by a melee attack, you can use your reaction to deal cold damage to the attacker equal to half your sorcerer level, rounded down. The attacker must make a Dexterity saving throw, with a DC equal to 8 + your proficiency bonus + your Charisma modifier or be knocked prone as ice appears beneath their feet. You also gain +2 to hit with any spell that deals cold damage if it has an attack roll and anyone that must make a saving throw against cold damage spells has -2.

Cyromantic Authority

At 18th level, you may spend 5 sorcery points to use one of the following effects.

• As an action, you summon a large archway of ice in two targetted locations which must be within 30 feet of eachother. Any ceature within 10 feet of the bottom of the archway must succed a dexterity saving throw against your spell save DC or take 5d10 cold damage.
• As an action, you reinforce your current armor with ice. Your AC is increased by 5, until you get hit three times. Aswell as that, whenever you get hit by a melee attack, shards of ice fly off your body. Your attacker must make a dexterity saving throw against your spell save DC of take 3d6 cold damage.
• As an action, you can create a beast of pure ice, the construct must be a Beast of CR 2 or under. It uses the stats of the creature you created, except it only has 50% of the health it originally had and any damage it dealt is changed to cold damage. If the creature is reduced to 0 hit points, it explodes. Any creature within 15 feet of the beast must make a dexterity saving throw against your spell save DC, if they fail they take 2d12 cold damage and on a success, they take half of that.