As two actions, you create a cloud of poisonous, yellow-green fog in a sphere centered on a point within 20 meters. The cloud spreads around corners and is heavily obscured. It lasts for the duration or until a wind of moderate or greater speed (at least 15 kilometers per hour) disperses it.
A creature that enters the spell’s area for the first time on a turn or starts its turn there must make a Fortitude saving throw.
On a failure, it takes 3d4 poison damage and is poisoned until the end of its next turn.
On a critical failure, it takes twice as much damage.
On a success, it takes half as much damage.
On a critical success, it takes no damage.
Creatures are affected even if they hold their breath or don’t need to breathe.
As an action, you can cause the cloud to move 2 meters in a direction that you choose at the start of each of your turns. As an action, you can stop the cloud from moving if it is within 20 meters of you.
You can increase the damage by 1d4 for each additional mana expended.
You can expend 1 additional mana so duration changes to 1 hour/mana.