Wall of Mercury

Upon casting this spell, you create a wall of swirling mercury up to 60 feet long, 20 feet high, and 1 foot thick at a point you can see within range. The wall appears as a shifting liquid mirror and remains in place for the duration.

Any creature that starts its turn within 2 feet of the wall or moves through it for the first time on a turn must make a Constitution saving throw. On a failed save, the creature takes 4d8 poison damage and is poisoned until the end of its next turn due to the toxic nature of mercury. On a successful save, the creature takes half as much damage and isn’t poisoned.

The wall also has volatile properties due to mercury’s high thermal conductivity. Any fire-based spells or attacks that hit the wall cause it to explode in a 10-foot radius. Creatures within this radius must make a Dexterity saving throw or take 2d8 fire damage, half as much on a successful save. Creatures failing the saving throw are also poisoned from the vaporized mercury cloud taking 4d8 poison damage and are poisoned until the end of its next turn due to the toxic nature of mercury.