Rime Mage

Rime mages master the use of cold magic to yield effects both constructive and destructive. Creating fortresses, freezing foes, and changing the environment around you are just a few of the abilities you will possess as a Rime Mage.

Frigid Soul

Beginning at 1st level, your adaptation to the frigidness of the environment around you gives you resistance to cold damage. You also learn the Frostbite cantrip which doesn't count against the number of cantrips known. When you cast a spell that deals cold damage, Frostbite can be cast as a bonus action on that turn. Finally, icy terrain doesn't affect your movement.

Arctic Bastion

At level 6, your affinity with the cold has allowed you the ability to create works of ice that resemble structures of stone. Your body becomes encased in icy crystals that form a defense against attacks. Your AC is equal to 13 + your Dexterity modifier while you aren't wearing armor. Additionally, you can add your charisma modifier to any cold damage you cause with a spell.

At level 11, you learn the Wall of Ice spell and it doesn't count against your spells known.

Icy Tomb

Starting at level 14, when you damage a creature with a spell of 1st level or higher that deals cold damage, you can expend a number of sorcery points equal to the spells level to force the target to make a constitution saving throw or become frozen in ice until your next turn. For the duration, the target suffers from the petrified condition. 

Master of Ice

At level 18, your command over the forces of winter is so great that you have learned to become the master of ice. As a bonus action, you can cause swirling, frigid winds to surround you in a 10 foot radius that end when dismissed by you or if you are incapacitated. Any creature that enters the area for the first time on a turn or starts its turn there takes cold damage equal to your charisma modifier each round that the creature is within the winds. Additionally, projectiles have disadvantage to hit you while the winds swirl around you. Water freezes solid until the end of your next turn if in contact with the aura. Finally, any creature within the aura can be affected by your Icy Tomb feature if they take damage. You can dismiss the aura with a bonus action.

You can also expend 6 sorcerer points to expand the aura to a 30 foot radius for 1 minute and deal additional cold damage equal to your level within the radius. Once you use your Master of Ice feature in this way, you must take a long rest before you can use the feature again.