Techtonic Bloodline

You are a creature of the earth,  your magic comes from the Elemental Plane of Earth.  Whether it be directly or indirectly, somewhere in your bloodline your blood was infused with the magic of this elemental plane.  Typically these people feel connected with the earth, it caves, its soil, and all things that grow from it. 

Earth Speak

You can speak, read, and write Terran.

Subterranian Awareness

You gain a tremor sense of 30ft

Expanded Spell List

You gain access to an expanded spell list

Earthen Resistance

As magic flows through your body, the toughness and resilience of stone is surfaces on your skin. At 1st level, you gain resistance to bludgeoning damage.

Additionally, parts of your skin are rugged to the touch. When you aren’t wearing armor, your AC equals 13 + your Constitution modifier.

Stone Fortitude

Starting at 6th level, You gain a use of stones endurance, as well as advantage on constitution saving throws against poison and thunder while you're touching the ground

Stone Swim

At 14th level, you gain a burrowing speed equal to your current speed.  If you are hidden from a creature while you are underground, when you cast a spell on it, the creature has disadvantage on any saving throw it makes against the spell this turn.

Creatures with tremor sense cannot be affected by this ability.

Techtonic Transformation

As an action, once per long rest, you can spend 5 sorcery points to transform into an Earth Elemental. You maintain your mental stats, proficiency in any skills and ability checks you already have, as well as your ability to cast spells.  This transformation lasts an hour or until your hitpoints are reduced to 0, in which case you take any damage that the earth elemental form could not.