Ordainment of crystal

Casting Time: 1 action
Range: Self
Components: V, S, M (a diamond worth at least S00gp)
Duration: Concentration, up to 10 minutes

9th-level transmutation (Sorcerer, Wizard)

Your body transforms entirely into magical crystal for the duration. Choose either force or radiant damage.

You gain the following benefits while transformed:

You have resistance to all damage.
You ignore the effects of disease, exhaustion, and poisons. Any poisons or diseases already in your system are suspended, not neutralized.
When you cast a spell of 1st-level or higher, you can choose one or two creatures that you can see within 60 feet of you. If you chose only one creature, that target takes damage of the chosen type equal to 2d6
twice the spell's level. Otherwise, each target takes damage equal to 1d6 + the spell's level. Treat this damage as if it had come from the magic missile spell (for example, it is blocked by the shield spell), but it ignores resistance to the chosen damage type.
When another spell you cast deals damage of the chosen type, it ignores resistance to that type, and it deals extra damage of that type equal to 10 + twice the spell's level. A spell can't deal this extra damage to any creature more than once per turn.