Earthborn

A Sorcerous Origin from the Plane of Gaian with mineral-grain armor, resistance to nonmagical bludgeoning, immovability, a burrow speed and stone walls.

Identity

The Earthborn is the Sorcerous Origin from the Plane of Gaian, the foundation the cosmos is built on. Earthborn are slow to move and difficult to move, and they think on a geological scale. The trait shows in Nordvergur deep-holds and in frontier families three generations into a rock that did not want them. Their spellwork favors weight, walls and ground.

Features

L3 Mineral Skin

Your skin has a mineral grain. While you wear no armor, your AC equals 13 + your Dexterity modifier. You also have resistance to bludgeoning damage from nonmagical attacks. You know the Mortar cantrip, and it does not count against your cantrips known.
L7 Immovable

You cannot be moved against your will while standing on solid ground. You have advantage on saving throws against being knocked Prone, and you have a burrowing speed of 15 feet through earth, sand or loose rock.
L11 Stone Wall

As a bonus action, you can spend 2 Spell Points to raise a wall of stone in an unoccupied space you can see within 30 feet. The wall is 10 feet long, 5 feet high and 6 inches thick. It has AC 15 and hit points equal to five times your Sorcerer level, and it lasts 1 minute.
L15 Form of Gaian

As a bonus action, you can spend 5 Spell Points to take on the plane's own substance for 1 minute. You have resistance to all nonmagical damage, your speed is halved and cannot be reduced further, and your spell attacks deal an extra 1d8 bludgeoning damage.
L18 Settled Ground Capstone

Once per long rest, as an action, you can settle the ground in a 60-foot radius for 1 minute. The ground there is difficult terrain for creatures hostile to you. No creature there can be teleported or moved against its will except by you. A hostile creature that begins its turn there must succeed on a Strength saving throw against your spell save DC or be Restrained until the end of its turn.