Soon after landing in the forest, Ren is ambushed by a King Taijitu in a small grassy clearing, which he senses beforehand with the help of his Aura.
Approaching him from behind, the King Taijitu slithers around Ren and gathers itself in front of him, before making two large strikes with its head. Ren avoids the first and blocks the second, sending him sliding a good distance. The snake-like Grimm immediately coils itself around Ren, prompting the Huntsman-in-training to draw StormFlower.
As the King Taijitu continues to coil around him in an attempt to smother him, Ren leaps upwards and narrowly escapes the Grimm's efforts. While in midair, he fires many rounds from his weapon, and when the Grimm retaliates, he kicks it in the face.
As the Grimm starts to recover from the hit, Ren closes in and slashes it with one of the blades on StormFlower. Managing to recover anyways, the King Taijitu gains some distance before making a fast charge at Ren. Ren jumps over the strike, which was so fierce the impact zone began to splinter and crumble. Using the momentum from his jump, Ren lands on the King Taijitu's head, impaling it with both bladed ends of StormFlower.
The white end of the King Taijitu becomes active, and strikes at Ren, forcing him to gain distance. Both heads of the King Taijitu become active and move in concert to attempt to kill Ren. Using their smooth scales as a makeshift slide, Ren moves around the coiled mess, dodging where necessary and getting off plenty of shots with his pistols.
Eventually, the white head finds an opening and hits Ren out of the air, also causing him to drop StormFlower. Immediately following up, the black head dives at Ren with its mouth open. Projecting his Aura as a shield, Ren manages to block the King Taijitu's charge.
Grasping at the fangs in the Grimm's open mouth, he tears both fangs right out of their sockets. Despite its pain, the black head attempts another charge at Ren, but he easily dodges and stabs one of the fangs into the King Taijitu's eye. Swiftly, Ren deals a vicious palm strike, presumably charged with Aura, to the fang in the creature's eye. The force is so great that the fang acts like a bullet, surging through the King Taijitu's skull, utterly destroying its head and effectively killing the black side. He then dashes toward the white end.
The remainder of the fight is not shown, but at the end of the episode, Ren is shown to have been triumphant, with the other end of the Grimm down as well.