You create up to a 65 ft. cube of clouds suffused with arcane energies.
(If multiple Arcane Clouds overlap the same space, only the most damaging one deals damage.)

Any creatures within the cloud when it is created do not take damage from the cloud until their turns.

The cloud provides concealment.
(Shapesense, tremorsense, and lifesense ignore this concealment.)
While a creature is within the cloud, it is blinded and concealed.
The cloud imposes disadvantage on tests of seeking through it, unless a creature can see through it.

Any creature which starts its turn in, spends any part of its turn in, or ends its turn in the cloud
must pass a DC 16 health save
or take 1d6 elemental damage,
+1d6 elemental damage per boost from Intensify,
and does not take damage from any Arcane Clouds again until the start of its next turn.

If you want, you may create a cloud which deals no damage instead.
On each of your turns, you may move the cloud 5 ft.

Dissipate d4:
At the start of each of your turns, roll a d4. If you roll a 1, the cloud disperses.
A strong wind can disperse the cloud sooner, or move it.

You can end this spell as a fast action.

Suggested Backfire: The cloud appears centered on you. Or your spellburn die size decreases.