A storm cloud appears in the shape of a cylinder that is 10 feet tall with a 60-foot radius, centred on a point you can see 100 feet directly above you. The spell fails if you can't see a point in the air where the storm cloud could appear (for example, if you are in a room that can't accommodate the cloud).
When you cast the spell, choose a point you can see within range. A bolt of lightning flashes down from the cloud to that point. Each creature within 5 feet of that point must make a Dexterity saving throw. A creature takes 3d10 lightning damage on a failed save, or half as much damage on a successful one. On each of your turns until the spell ends, you can use your action to call down lightning in this way again, targeting the same point or a different one.
If you are outdoors in stormy conditions when you cast this spell, the spell gives you control over the existing storm instead of creating a new one. Under such conditions, the spell's damage increases by 1d10.
At Higher Levels: When you cast this spell using a spell slot of 4th level or higher level, the damage increases by 1d10 for each slot level above 3rd.
Until the spell ends, one willing creature you touch gains the ability to move up, down, and across vertical surfaces and upside down along ceilings, while leaving its hands free. The target also gains a climbing speed equal to its walking speed.
You touch a willing creature. Until the spell ends, the target's skin has a rough, bark-like appearance, and the target's AC can't be less than 16, regardless of what kind of armour it is wearing.