We start to learn a bit more about the Hearts in episode 16, which begins with the five of them relaxing together (we see them here without stage make-up for the first time). Fujimaru says something to Kazuya about the Reideens which prompts a short speech from the group leader. What he says makes Fujimaru look thoughtful and rather sad. At the same time, Shinobu is doing stretches on the floor, Masato is practising his bass, and Kyle is reading a magazine.
Meanwhile, we see the redheaded serpent-demon girl is still around and thinking about Ginga. Lúci is shown with another female demon (blue-haired) whose power apparently involves water.
The Hearts are shown doing a radio interview with Kirari as the interviewer. Kyle (who speaks very formally and politely in Australian-accented Japanese) discusses his past and we see a flashback. He's shown in an alley with a drum kit, where a group of four or five tough guys find him. They beat him up and prepare to cut off his hand. As the knife comes down, someone gets in the way, taking the cut across his back for Kyle. It's Kazuya (with shorter hair), and when he turns around, the look in his eyes is enough to scare off the toughs. Understandably, Kyle has a lot of respect and admiration for Kazuya.
We see the Angels at rehearsal, once again talking about the new Reideens. Kyle enters wearing a kimono and a hat that looks like an upside-down wok, waving a fan with a little heart on it. The Angels don't seem to know what to make of him at first, but Ace recognizes him as the Hearts' drummer. Kyle says something about the Reideens, jumps onto the stage, and knocks Hayate and Ikazuchi off. He uses two drumsticks that shoot out rope-weapons such as Reideen Isis used (which of course, the others recognize). It's noteworthy that he's using this power while not in Isis form.
Meanwhile, the blue-haired female demon has created a demon of her own from a waterfall--it's a carousel with two bickering horses on it. The carousel is shown on a tv report that Hishou's mother, sister, and Reiko are watching.
Back at the rehearsal hall, all of the Angels have been floored by Kyle except for Ginga, who is about to take him on when Reiko shows up. Kyle's transformation into Reideen Isis is shown--no computer animation. A cool rainbow encircling him is part of the transformation. Reiko looks very impressed by Kyle, both before and after the transformation (calls him 'bishounen'). He leaves, but the Angels argue because Hayate and Ikazuchi don't seem interested in going to investigate the carousel since Isis is going. Hishou says something that inspires everyone to go after all.
Isis is hitting the carousel with his drumstick-spike weapon, it spins into the air and he goes after it. He kicks the carousel, which lands on the ground. It seals him in a bubble that he can't break. It prepares to wipe him out. Just as he is about to die, Kyle thinks something to do with Kazuya, but it's Reideen Hawk who saves him by getting in the way of the carousel. The carousel winds up to do something else while Hawk tries to get Isis out of the bubble. When Hawk and Isis both use power on the bubble from inside and out, it finally breaks. The carousel emerges again and Isis goes after it first. He changes into the bird-plane form, trailing rainbow colours as he flies. Hawk changes to bird-plane form as well and the two of them attack the carousel from either side. It is destroyed.
In street clothes, Kyle talks to the Angels. At first it looks as if things will get tense, but the Angels end up smiling, except for Ikazuchi, who hollers after Kyle as he flies away with a flourish.
The female demon who created the carousel is shown to be still lurking around.