Wall of Obsidian

You create a wall of obsidian rock on a solid surface within range. You can form it into a hemispherical dome or a sphere with a radius of up to 10 feet, or you can shape a flat surface made up of ten 10-foot-square panels. Each panel must be contiguous with another panel. In any form, the wall is 1 foot thick and lasts for the duration.

If the wall cuts through a creature's space when it appears, the creature within its area is pushed to one side of the wall and must make a Constitution saving throw. On a failed save, the creature takes 6d8 necrotic damage, or half as much damage on a successful save.

The wall is an object that can be damaged and thus breached. It has AC 15 and 30 hit points per 10-foot section. Any creature that touches the rock for the first time each turn or damages it at any time must make a Dexterity saving throw. That creature takes 3d10 fire damage on a failed save, or half as much on a successful one. Reducing a 10-foot section of wall to 0 hit points destroys it and leaves behind a layer of rubble as well as a cloud of smoke in the space the wall occupied. The rubble acts as difficult terrain, and any creature moving entering the cloud or starting its turn there must make a Constitution saving throw. On a failed save, the creature takes 2d8 poison damage and is poisoned for 1 minute.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the damage the wall deals when it appears increases by 1d8, the damage from touching or harming the rock increases by 1d10, and the damage from passing through the smoke increases by 1d8, for each slot level above 5th.