You have Resistance to Fire damage and Cold damage.

You have Darkvision with a range of 60 feet.

You know the Elementalism cantrip. Charisma is your spellcasting ability for it.

When you reach character level 3, you can transform as a Bonus Action using one of the options below (choose the option each time you transform). The transformation lasts for 1 minute or until you end it (no action required). Once you transform, you can’t do so again until you finish a Long Rest.

Once on each of your turns before the transformation ends, you can deal extra damage to one target when you deal damage to it with an attack or a spell. The extra damage equals your Proficiency Bonus, and the extra damage’s type is either Cold for Icy Shroud or Fire for Fiery Radiance.

Here are the transformation options:

Fiery Radiance. Fire erupts from your body. For the duration, you shed Bright Light in a 10-foot radius and Dim Light for an additional 10 feet, and at the end of each of your turns, each creature within 10 feet of you takes Fire damage equal to your Proficiency Bonus.

Icy Shroud. Ice forms a protective layer over your body. Your AC increases by 2, and at the end of each of your turns, each creature within 10 feet of you takes Cold damage equal to your Proficiency Bonus.