Circle of the City

The city lives; it has a pulse. Its skin is of walls and towering stone structures, its breath is of chimneys and rivers. While the city exists, it lives in harmony with its people, a delicate balance mediated by the urban druids. These urban druids belong to the Circle of the City and are a direct antithesis to the conventional idea of a druid; whereas a normal druid lives among majestic forests or breathtaking mountains and dresses in the greenery of the wildnerness, an urban druid wears unassuming clothes and wanders the back alleys of a well-trodden city. But their powers are not to be underestimated.
Druids of this circle can channel their natural powers to twist the streets into knots, uproot towers, and animate the cobblestones. Their charge might be unorthodox, but their authority over the cityscape matches any druid's power over the forest.
Urban Arcana: Beginning when you choose this circle at 2nd level, your druid spells lose the aesthetic trappings of nature and instead appear inspired by the jungles of buildings, columns, and cobblestones. For example, entangle and spike growth might cause growths of metal wires and twisting pipes. Barkskin might grant you the appearance of pitted iron or brick.
Additionally, you can wear armor and wield shields made of metal.
Streettalk: At 2nd level, you have advantage on Investigation checks to gather rumors or find a creature or location within an urban environment.
Additionally, you learn thieves' cant, a secret mix of dialect, jargon, and code that allows you to hide messages in seemingly normal conversation. Only another creature that knows thieves' cant understand such messages. It takes four times longer to convey such a message that it does to speak the same idea plainly.
City Shape: Starting at 2nd level, as an action, you can expend a use of your Wild Shape feature to warp the city around you. Choose one of the following effects:
Cobbleshift. You magically manipulate the components of a constructed floor -- bricks, cobblestones, planks, and similr objects -- within 60 feet. Each component can move up to 1 foot, and doesn't cause instabilities in their structures. When you use this effect, you can cause any sections of floor thta you choose within the area to become difficult terrain, and can cause any creature standing in one of those sections to make a Dexterity save against your spell save DC or fall prone. You are unaffected by this difficult terrain.
Additionally, you can use your action on each of your turns to raise up to three low walls from the floor, each 2 and 1/2 feet high, 5 feet wide, and 1 foot deep. Such a wall can generally provide half cover for a Medium creature. These walls provide no instability in surrounding structures.
This ability lasts for 1 minute. After this time, all componoents and walls magically revert to their original positions.
Passwall. You can cast the spell passwall without expending a spell slot or material components.
Wall Warp. A wall that you can see within 30 feet magically shifts, grows, shrinks, or rotates. This wall must be a contiguous surface without corners, at most 1 foot thick, and must be made out of wood, plaster, stone, or must otherwise not be naturally occuring. The wall must remain vertical, but you can move it into any position you choose within a 60-foot radius of its previous position. Its new position can't include spaces occupied by creatures or objects. If you cause the wall to grow or shrink, you can only change its dimensions vertically. These changes to the wall create no instability in their structures. After 1 minute, the wall reverts to its original size and position.
Whispers of Walls: Beginning at 6th level, the walls speak to your in a quiet tremor. You can use your action to touch a constructed part of a building, such as a wall, pillar, ceiling, or floow. You learn how many humanoid creatures are within that building and how many are within each room. If there are more than 50 humanoids in a building, you only detect the closest 50.
You can use this ability a number of times equal to your proficiency bonus and regain all uses when you finish a short rest.
Breath of Smog: Starting at 10th level, you can exhale a 10-foot rdius sphere of toxic smoke, centered on yourself, as a reaction whenever you take damage. This area is heavily obscured. If a creature other than you is completely within the smog at the start of its turn, it must make a Constitution saving throw against your spell save DC, or be poisoned until the start of its next turn, as it coughs uncontrollably.
This smog dissipates after 1 minute. A moderate wind (at least 10 miles per hour) disperses the cloud after 4 rounds. A  strong wind (at least 20 miles per hour) disperses it after 1 round.
Once you use this ability, you can't use it agian until you use your City Chape feature or you finish a short or long rest.
Twisting Architecture: By 14th level, you command total mastery of the city's architecture, warping to any shape you might imagine. You can use two uses of your Wild Shape feature to activate any and all effects of your City Shape ability at one time.
Additionally, when you use your City Shape feature, you can warp the gravity along any surfaces you choose within a 60-foot radius. For the next minute, creatures and objects within 15 feet of one of these surfaces fall toward it as if it were the ground. A creature can walk on this surface as if it were level ground, even if the surface is perpendicular to the ground or upside down. At the end of this duration, all creatures and objects fall from the affected surfaces.