Frozen Soul

The Frozen Soul sorcerer is a defensive and crowd control focused class, wich deals more damage to targets with impaired movement. 

In this class many abilities can "freeze" creatures. A frozens creatures speed becomes 0 and it cant take actions or reactions, attacks against the creature are made with advantage and the creature is resistant against slashing and fire damage, but vulnerable to bludgeoning and thunder damage.

Legacy of the Cold

While not wearing heavy or medium armor you can use a bonus action on your turn to form a icy armor. This armor grants you a AC of 13+Con and lasts until you drop to 0 hp or dismiss it as a free action. You also have resistance to cold damage and are immune to the effects of Cold climate. 

Cold Affinity

Starting at 6th level, when you cast a spell that deals cold damage or impairs the movement of a creature the spell can deal additional damage equal to your charisma modifier, even if the spell normally wouldnt deal damage.

Chilling Gaze

As a reaction when a creature within 15 ft. of you attacks you can spend 3 sorcery points to use your reaction to force the creature to make a dexterity saving throw. On a Failed save the creature is frozen until the start of its next turn. You have to use this reaction before it is determined if the attack hits or misses. If the creature is frozen that way the attack misses regardless of the atack roll. 

Frozen Storm Aura

At 18th level, you gain the ability to call a freezing storm in a 20 ft. radius around you. Ranged attacks that pass through the aura are made with disadvantage and the speed of all creatures, including you is halved. Creatures other than you, that enter the aura for the first time or start their turn in it must make a constitution saving throw. On a failed save they freeze  until the start of their next turn and take Cold damage equal to your sorcerer Level. On a succesful save they are not frozen and the damage is halved. Frozen creatures make this saving throw with disadvantage.

You can create this aura as an action on your turn. It lasts until you dismiss it as an action on your turn, you loose concentration, or you are incapicitated.

When you dismiss the aura you deal 1d12 bludgeoning damage to each creature in the area and all frozen creatures are unfrozen as the ice shatters. For each frozen creature in the area the damage increases by 1d12. Frozen creatures that are reduced to 0 hp through this damage shatter into ice shards and die.