Lin Yuan never underestimated his feys or overestimated his opponents.
He had internally rebuked Xia Qing's words because he understood Liu Jie.
The Sky-Questioning Flaming Heart Mushroom could release hundreds of thousands of spores into the air. As long as five spores made it into the body of a Diamond insect, the Sky-Questioning Flaming Heart Mushroom would be able to trigger its ability.
However, high-level insect-species carcinoma feys multiplied into an army much faster than was expected by the average person. This especially applied to an army created by multiple insect-species carcinoma feys.
With the neverending waves of insect armies charging at him, it would be difficult for Lin Yuan to use the Sky-Questioning Flaming Heart Mushroom to take control of the vast number of insects within a short span of time.
There were some insect-species carcinoma feys that could even consume the Sky-Questioning Flaming Heart Mushroom's spores.