Crippling Cloud

Gently blowing over the top of a vial of poison, a purple cloud of crippling miasma seeps out from you in a 20 foot cone. The cloud spreads around corners and over small barricades.

Each creature that is completely within the cloud must make a Constitution saving throw against poison. On a failed save, the creature takes 4d6 poison damage, and the creature deals only half damage with weapon attacks that use Strength until the spell ends. 

At the end of a creature's turn, it can retry the saving throw against the spell. On a success, the spell ends.
Creatures that don't need to breathe or are immune to poison automatically succeed on this saving throw. 

If this spell is cast during a strong wind (at least 20 miles per hour) then creatures affected by the spell have advantage on their saving throws.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the size of the cone increases by 10 feet.