You conjure the raw elements from an attack you've been dealt and turn yourself into the living embodiment of those elements. When you take damage of any type, you can cast this spell as a reaction to give yourself resistance to that damage. Afterwards, your body transforms itself into a living form of that damage type, granting you total immunity to that type of damage. When you deal damage from attacks and spells, you can alter that damage type to match your elemental form's, which deals an extra 4d12 of that damage type each time you use this ability.

While you are in an elemental form you are semi-incorporeal, able to fly up to your movement speed, move through creatures, and through thin spaces no smaller than an inch in diameter. If you end your turn inside a space occupied by a creature, you are shunted out into an empty space next to it and take 1d12 force damage. If your form is from physical damage, as in being immune to either bludgeoning, piercing, or slashing, you are instead completely solid, flightless with a +2 to your AC and you have resistance to every other type of physical damage. Creatures who start their turn within 10 feet of you take 2d12 damage of your element type and as a bonus action you can have them take this damage again. 

As long as this spell is active, you can use your reaction to give yourself resistance to any oncoming damage and adapt to that element's form.