Underworld Valley Posion

With a single swift motion, Yuan waved his hand, conjuring multiple dark green insects that materialized in the space around them.

Kai's gaze remained fixated on Yuan as he went on to perform a series of intricate hand seals, each seal imbuing the insects with newfound energy. With every passing moment, the insects grew in size, their bodies pulsating with an ominous green glow that seemed to throb with a malevolent power.

Soon, a dense green mist began to emanate from their enlarged forms, filling the surrounding area with a noxious haze that whispered of impending doom. 

Effortlessly, the mist coalesced into a protective dome, encapsulating both Kai and Yuan within its ethereal boundaries.

A glimmer of excitement danced within Kai's eyes as he observed the swirling currents of the toxic gas encircling him. "I can assume this is far from a ordinary gas, correct?" he inquired, his voice tinged with an equal measure of curiosity and amusement.