Blood of a Frost Phoenix

Ice themed sorcerer

Icy Viens

Starting at 1st Level, ice runs through your blood and because of it has giving you an upper hand when it comes to cold.

The following traits are given to you:
You learn the Armor of Agathys, this does not count against your total known spells, once per short or long rest you may cast this spell for free, at 3rd lvl you now cast it at the level of your proficiency modifier.
You are acclimated to colder conditions. Moving through difficult terrain caused by ice or snow costs you no extra movement and you are unaffected by temperatures as low as −50 degrees Fahrenheit.

Frost Fire

At 1st level you learn the secret of frost fire. When you cast a spell that deals fire damage, you can have it deal cold damage instead.

Ice Ward

Starting at 6th level, when you or a friendly target within 15 feet of you are about to take slashing, piercing, bludgeoning, or fire damage, you can use your reaction to reduce the damage taken by your sorcerer level.
If the damage is reduced to 0, the target gains +1 AC until the end of their next turn.

Flash Freeze

Starting at lvl 6, all cold spells you cast adds your Charisma Modifier to the damage of them.
When anyone takes cold damage from spells of 1st level or higher you can reduce their by 10 ft. by spending a 1 sorcery point.
You gain resistance to cold damage.

Born of the Frost

Starting at lvl 14, once per long rest when you are reduced to 0 HP instead of taking death saving throws you may choose to be encased in ice until the start of your next turn. At the beginning of your next turn, you are conscious with 1 HP. Any creatures of your choosing that are within 20 ft of you must make a DEX saving throw of your spell DC or take 4D8 + your CHA modifier Cold damage. On a successful save the damage from this is halved.

Frozen to the Core

Starting at lvl 18, you gain immunity to cold damage and resistance to fire damage.
Your frost spells also freeze your enemies in their tracks. When a creature fails a saving throw against a spell of 1st level or higher that deals cold damage, they are restrained until the start of your next turn.