Contrary to what the Tai Sui Army guide suspected, Huang Quan likely hasn't truly mastered the technology to manipulate the Great Demon.
If Huang Quan could achieve such a feat, he could easily coordinate with the Great Demon Xuanwu now to execute more skillful combined attacks. Even if his manipulation skills are still immature and he can only give the Great Demon the most basic instructions, he wouldn't appear so tied up like he does right now.
He should at most be able to make the Great Demon Xuanwu ignore him.
Even though it's a difficult situation with one against two, this human god and Great Demon haven't demonstrated the advantage of numbers greater than the sum. Currently, they're completely like two "strangers." In fact, even strangers can achieve basic rapport when facing a common enemy, yet the Great Demon Xuanwu entirely lacks that partner awareness.