In the end, overcome by a sense of familiarity, Sun Wukong did not kill the Red Jiao but instead transformed into his giant demon form and swallowed it, secretly transporting it into his own small world.
He directly delineated an area, transported lava, and replicated the smelting environment for it.
The Red Jiao, having narrowly escaped death, trembled in its demon form when it sensed the surging spiritual charm and the omnipresent rules of the small world, revealing a humanlike shock.
...
Outside.
In the roiling lava, Sun Wukong returned to his normal size and walked towards the location of the snake hole.
At this moment, the snake hole had collapsed, and debris was strewn everywhere.
Sun Wukong picked up a piece of debris and found it to be extremely hard, and indeed, it was a rare spiritual material.
"This is perfect since the monkey tribe lacks weapons. I can collect it for them to forge their own."