The chapter started with Amaimon attacking the lot, and the female instructor (I can't remember her name) defended the group by summoning a snake, which is probably from her magical barrier. Amaimon, who was repelled to somewhere near Mephisto, was warned that if he kills anyone there, Mephisto would kill him. And by the way, Mephisto was sipping tea in an armchair in the sky. LOL.
The female instructor started giving out instructions to the group to defend against Amaimon, and the group (other than Rin) were shocked to find out that the attacker is Amaimon, the King of Earth. She sprayed everyone but Rin with an extra strong dose of holy water (well, she nearly sprayed it on him too, but stopped just in time XD). It seems that the holy water is like an armour, and will minimise any injuries they sustain until the water on their bodies evaporates. When asked about why Rin didn't need the water, she actually said that he was sensitive to holy water! XDDDD
In response to the group's queries about Yukio, she commented that he was getting in the way and sent him out on another errand. It seems that the (giant) moth demon was reared by an exorcist and it should not have been attacking the trainees, and he wonders about what is going on.
Meanwhile, Bon wonders about Amaimon's purpose for attacking them. Rin approached the female instructor and told her that he knows Amaimon is after him. She replied that she knew about it, and hence she set up a barrier just to combat demons of his level. And she said that she tried planning for this, and told Rin to take his demon sword and run when Amaimon attacks again. She chanted something and the sword actually came out of her navel where there's this weird tattoo (or maybe, it's just a scar). O_O <-- That's Rin's expression, and the instructor asked him what was wrong and told him to take the sword. It appears that no one was paying attention to their conversation.
Rin asked her why she was returning him his sword when he hadn't even defeated her yet, and she replied that that was not the only condition that she had mentioned for her to return him his sword. The other condition was based on her judgement, and Rin pretty much shouted at her saying that she had told him not to use his flames, so she shouldn't return him the sword yet. She said that he'd still used it either way, and he had nothing to counter that.
To cut the story short, she's returning him the sword because he's probably the only one in the group who can defeat Amaimon, and he needs his flames to do that. But she doesn't say that outright, and tells Rin to think about it himself.
Suddenly, Shiemi walks into the forest without a word, and Rin realises that there's a parasite on her neck. The instructor raises a sword to Rin's throat and asks him what he'd done to Shiemi. Amaimon appears beside Shiemi and explains that he'd let the moth lay eggs in Shiemi's neck (eww) and when the eggs hatched, Shiemi will be completely under his control (and hugs a dazed Shiemi). Shiemi actually looks nicer when she's dazed. Maybe the mangaka should draw more pictures of a dazed Shiemi. XDD
Rin runs after Amaimon, calling him a carrot head. LOL. Just as he stepped out of the magical barrier, a demon appears. The instructor hits the demon away and gets Rin to go ahead, and that she'll catch up later. And she'd also forbidden anyone else to step out of the barrier, and Bon grumbles about Rin doing everything alone again.
Rin catches up to Amaimon and Shiemi, asking him what was his purpose in catching Shiemi. Amaimon thought for a second and replied that he wants her as his bride. After which, he started reciting the marriage vows. When he was about to kiss her, Rin asked him what kind of a joke was that and whacked him on the head with his sword. XDD Amaimon dropped to the floor immediately. He threw Rin up into the sky where Bon and the others could see him and said that that was the sentence he wanted to throw back at Rin - what was the point of a sword if he doesn't draw it? Everyone had identical shocked expressions, and the instructor said that he shouldn't take things too far.
Rin fell onto some rocks and lost consciousness. Bon got so pissed off that he ran out to meet Amaimon, while the others tried to stop him by saying that it was dangerous and he should calm down.
Bon replied that he was super pissed now and he was so calm that he would bite it even if it's a dog. The bald guy (forgot his name, sorry) wonders what's up with Bon, sighs, and runs after him. LOL. The other girl (forgot her name too >< ) thinks that they are all crazy and she doesn't want to die with them.
Amaimon wonders if Shiemi is someone important to him, and Rin told him to die while he coughed up blood. Amaimon said that he'd seemed to have caught someone unimportant, but that was okay, cause he can take one of her eyeballs as a souvenir for one of his brothers who asked for a collection of human eyeballs. Rin told him to stop it. A firework zooms past Rin as he shouted for Amaimon to stop it, and Bon tells Amaimon to come after him - Bon was trying to stall Amaimon for Rin and Rin told him to run.
Instead, Bon told Rin to run when the chance comes but Rin said that he was going to save Shiemi no matter what. Rin told everyone to run (cause the bald guy had arrived on the scene too) while Amaimon was confused about what was going on. The bald guy accidentally lights a firework and it seems to have hit Shiemi's face. >.> While they were panicking about it, it appears that the firework had hit Amaimon's antenna-like hair and it became a cabbage flower. XDDDDDD
Amaimon jumped and kicks the guy who laughed. Uh, the guy who is not the bald guy. I can't remember all of their names! >< Amaimon then turns towards Bon and the bald guy runs in front of Bon to shield him. Amaimon pokes his elbow and I believe his bones broke. He then goes to Bon, gets him in a chokehold and tells him not to laugh at him.
Bon said that it had nothing to do with Amaimon. The one making him angry is Rin, who was always doing things on his own although he had no special abilities. Saying that Rin was full of mysteries, Bon asked Rin what kind of a guy he was. A pissed-off Amaimon told them not to keep him out of their conversation and chokes Bon even more. Rin shouts for him to stop it (again - he's been doing that a lot).
Rin stands up, and takes his sword holder off (not the shealth, it's a piece of cloth). As he stared down at everyone, he thought of what they'd told him about him not being alone and how everyone was so gentle to him.
Yukio finally appears on the scene and tells Rin that it was a trap. But Rin said that he had always been lying and pretending to be dumb, and he wanted to face the truth cause he wanted to use his flames in a gentle way too. He pulls out his sword and reveals his true form. Everyone looked shocked. Rin tells Amaimon that he is his opponent. The latter laughed and rushed up to fight him. The bald guy asks Yukio what was going on but Yukio told him to escape and that things will be explained later.
Bon stares at Rin's sword and says that the sword is a (divine? demonic?) sword called something something dragon king (cause I've no idea how to translate that, but it's apparently one of the dragon kings in Buddhism).
The fighting continues between the two and Amaimon joyfully exclaims that it's so beautiful. Rin stabs him in the back and tries to burn him but Amaimon managed to get away.
Laughing, Mephisto, who is still floating in the air with his armchair, comments that a demon's tail should be hidden properly by a gentleman (more like "gentle-demon") and that this was a lesson that Rin had to learn. Rin still had a lot more to learn about himself and the first thing he had to learn was his desire.
Meanwhile, Yukio extracts the parasite demon from Shiemi and the female instructor caught up with him. It appears that the demon Yukio was after had escaped so he returned to camp. The instructor orders an immediate retreat from the forest. She was thinking that Shiro had been taking care of such a monster (meaning Rin) for so long.
Mephisto commented that demons had always been denied of the right to pursue happiness because it was out of the human range of happiness. He wonders how things will develop next for Rin.
An intense fight among the two continues as the two are burned. Suddenly, both of their heads were grabbed by Mephisto who told them to stop fighting before his school is burnt to ashes. The text on the panel reads "A forced time-out!?"