You transform into a living storm cloud, becoming a swirling mass of black clouds illuminated from within by flickers of lightning. While in this form, your only method of movement is a flying speed of 60 feet. You can enter and occupy the space of another creature. You have resistance to nonmagical damage, immunity to lightning damage, and advantage on Strength, Dexterity, and Constitution saving throws.    If a creature strikes you with a melee weapon attack, it takes 3d8 lightning damage.    You can pass through small holes, narrow openings, and even mere cracks, but you treat liquids as if they were solid surfaces. You can’t fall, and you remain hovering in the air even if stunned or otherwise incapacitated. You cannot talk or manipulate objects in storm cloud form, and any objects you were carrying or holding can’t be used, dropped, or interacted with in any way. You cannot cast spells while in this form.    As an action, you can attack an opponent up to 30 feet away, dealing 3d8 lightning damage on a hit. You can also use an action to bring down rain upon a 5-foot square within your reach, drenching it and putting out any nonmagical fires in that area. Finally, you can use an action to expand your form to encompass a 20-foot-radius area, unleashing the storm’s full fury in a burst of rain, wind, lightning, and thunder. Each creature in the area is drenched with rain, takes 3d8 lightning and 3d8 thunder damage, is deafened for 1d4 rounds, and is knocked prone. A successful Constitution saving throw halves the damage and negates the deafened and prone conditions. Taking this action uses up any remaining duration of the spell, and you resume your normal form at the end of your turn.