Okay. So since I started posting my Super Sentai story on both my Tumblr and Wattpad accounts, I decided to post this particular fanfiction featuring Seitenger and one of my favorite Super Sentai series, Kyoryuger that’s been in my mind (and in my flashdrive) for a long time now. Now, I know I only posted two of the episodes for Seitenger. But what you’re about to read here will contain some spoilers on how the series will run, despite the timeline of this particular fanfiction taking place several months after Seitenger’s finale.
Here’s how the fanfiction goes:
Resuming their normal lives as they tried their best to continue defending the world, the Seitengers manage to enjoy the peaceful times. In fact, they are busy preparing for a special day—Hideoki and Nanami’s birthdays since the two adults happen to have the same birthday, only different year. But then duty calls as their Shifters and Changers react in the middle of their planning for the celebration. Just as they do their usual jobs of protecting the citizen from the attack of the remaining Tareans and some weird creatures they didn’t even know (later learned to be the remains of the Deboss Army) despite Helen’s absence because of her travel to Europe in order to research for her next novel, they later encounter the Kyoryugers in separate locations.
Shuichi meets Kiryuu Daigo when he almost hit the man with his motorcycle. Eichirou and Akira meets with Udou Nobuharu and Fukui Yuko when Akira accidentally hit the older man with his soccer ball during his practice at the park and Eichirou noticing his dejected state. Itsuki meets Amy Yuuzuki and Yayoi Ulshade while busy looking for musical pieces that will help him with his new composition as he hums a lullaby that his mother usually sings to him and Erika. Misae meets Rippukan Souji when she recalls an entry from her father’s journal about his swordsmaster at Rippu School who happens to be a family friend and decides to meet the man but instead she meets an injured Souji that she heals using her ability. Erika meets Utsusemimaru while playing the piano as she plays Itsuki’s new composition that impresses and calms the man somehow. Amuro meets Ian Yorkland upon seeing him busy researching about the remains of the Zourima and the Gargonema that the Seitengers have fought earlier.
The Seitengers soon realize in secret of the Kyoryugers’ predicament with the help of Shuichi’s ability to determine one’s thoughts and past using touch upon holding Daigo’s hand for the first time. They learn that the people important to the other team (Fukui Rika, Gentle, Rippukan Genryu, and Doctor Ulshade) have been taken as hostages and the enemies demand the Kyoryugers to locate the Seitengers and bring them in order to save the hostages. But the problem is, the Kyoryugers do not know who the Seitengers are. Though they’ve heard the rumors about the new Super Sentai team, they do not have any idea about the Seitengers’ identity and a way to contact them.
Assuming an innocent act about the identity of the Utsuwa Sentai Seitenger, the Vessels made a firm promise that they will help the Kyoryugers save the hostages by finding the Seitengers. But the Vessels are initially clueless on how to actually save the hostages. The worst thing is that the Seitengers find out that the one in charge of kidnapping the people important to the Kyoryugers turns out to be the revived Princess Adana. Then Itsuki remembers something and mentions to his teammates that the Wise Deity Torin have been appearing in his dreams for the past two weeks before meeting the Kyoryugers, telling him about fusing two powerful melodies belonging to the Kyoryugers (the Earth’s true melody) and the Seitengers (the Priestess’ lullaby) into a single composition. The power coming from the combination of the two melodies seems to be their only shot in defeating Princess Adana and the remaining Tareans and Deboss Army still dedicated in eradicating the world. Another problem surfaces when they realize that the Vessels didn’t know the full version of the Priestess’ lullaby.
As soon as Itsuki finally finishes the composition with a few help, the enemies began causing chaos in the middle of the city. They arrive a bit too late and witness that the Kyoryugers have been held captive and the Seitengers’ Shifters and Changers have been forcefully taken from them as they did their best rescuing the Kyoryugers, disabling their transformations in return. It seems that even though their transformations have been disabled, the Kyoryugers seem to be unconscious to even realize the Seitengers’ identity. Torin later appears to the Vessels in spirit form to give advice to the frustrated and distraught Seitengers. Knowing that they can’t afford to let everything go on like that, with the full knowledge of the threat that Adana can bring to the world, and along with the promise that they have made to the Kyoryugers, the Vessels—together with the other three Kyoryugers who manage to prevent capture (Yayoi, Yuko, and Shinya)—decide to confront the enemy once and for all.
Meanwhile, the Kyoryugers did their best to escape from being held captive but to no avail. They recount their encounters with the Vessels (though they are still clueless about the Vessels being the Seitengers). Despite feeling slightly frustrated, they maintain their faith to the people who have promised them to find the Seitengers. A vision from a few allies gives them the reason to continue hoping, especially upon realizing that they hold the Seitengers’ Heaven’s Medallions. The Kyoryugers finally realize through the vision that the people they have recently met turns out to be the Seitengers themselves who have deep reasons for not revealing themselves to them as the Vessels made an oath to protect each other from various threats coming from the Tareans.
With the threat of killing the hostages in front of the powerless and bound Kyoryugers, the Seitengers later appear to the enemies soon after despite their Shifters and Changers taken from them. They fight the Gargonema and the Zourima but it appears to be a losing battle for them even with the help of the other three Kyoryugers. Even though Daigo and the others want to stop the Vessels from putting their lives in danger, Shuichi and the other Vessels manage to continue on because of the promise they have made to the Kyoryugers. The Vessels later surprise the enemy when they summon their personal weapons even in civilian form. The enemies and the Kyoryugers soon learn that even though the Seitengers’ Shifters and Changers have been taken, the enemies actually fail to retain the Heaven’s Medallions inside each of it. With that, the Heaven’s Medallions can still allow the Seitengers to use their powers even in their civilian form. The other three Kyoryugers know about it and go along with the plan of holding off the army forces and prevent them from proceeding with the execution of the hostages just until Eurya finally finishes her task as Hideoki imposes with the help of Nanami.
Since the Vessels hand over their Heaven’s Medallions to the Kyoryugers they individually met for safekeeping and tracking purposes, the other team learn that one more reason for doing so is to actually allow the Seitengers to summon the Kyoryugers’ personal weapons to be used in conjunction with their own. Shuichi uses the Gabutyra Fang with his Lion Fire Blade, Eichirou wielded the Stego Shield together with his Shark Water Spear, Itsuki have been armed with DriceLance alongside his Tiger Earth Slasher, Misae uses the Zakutor Slasher with her Falcon Wind Arrow in Bowgun Mode, Erika uses the Zandar Thunder with her Dove Light Striker, and Amuro wields the Parasa Shot together with his Dragon Thunder Impaler. They fight the grunt soldiers attacking them and manage to free the Kyoryugers. When they are about to free the other hostages, an explosion ensues to the area where the hostages have been bound. The Seitengers think they have failed to save the captives and that it is over until they all witness a pink lotus silhouette in front of the hostages acting as a shield. With that, they already know that it was the enemies who have failed to kill the hostages since the Vessels already know where the silhouette comes from. Helen reveals herself soon after, wielding her Tenkuureider and Peacock Illusion Fan in civilian form and accompanied by Spix and Elle. Elle helps the Vessels and the Kyoryugers recover and prepare themselves. Spix fights the soldiers who dares to attack Helen as she free the hostages and strengthens the girl’s shield.
Enraged, Adana is about to attack the Seitengers and the Kyoryugers when stops with another explosive attack. A faint melody has been heard on the background that stiffens the Seitengers as the rage of the explosion subsides. The Vessels soon remember that the melody is actually similar to the lullaby that their mothers would always hum to them ever since they were kids. Surprise fills them as they soon see the core five Seitengers’ immediate predecessors (Fuumiya Ryouta, Hoshiyama Ozuma, Tennouji Atsuko, Kinmura Eisuke, and Hiwara Mai), Mizuhashi Mariko, and Torin actually walking towards them. The Vessels learn that Torin have made a promise to Itsuki that he will do something to allow the composer and his teammates to see their parents again if he actually manages to combine the two melodies into one single composition. But Itsuki have been determined to fulfill Torin’s wish, even without the Wise Deity doing his end of the bargain. They also learn that the melody they have been hearing is actually the revered Priestess’ lullaby—the Seitengers’ melody, giving power to those who maintains their hopes burning in their hearts. That short reunion has been rudely interrupted, however.
As they have all been determined to end Adana and the rest of the armies for good, the Seitengers and the Kyoryugers manage to retrieve their transformation devices with Shuichi and Erika working on the offense while Eichirou and Helen on the defense. The two Super Sentai teams transform soon after and fight the grunts. Eurya, Candelira, and Luckyuro helps the two Super Sentai teams by releasing the power of Itsuki’s composition containing the Earth’s true melody and the Priestess’ lullaby—with Eurya creating the magical flute needed to play the song, Candelira singing the song, and Luckyuro playing the said musical piece with a violin alongside Eurya. Torin and the Seitengers’ immediate predecessors also provide help.
However, Adana unleashes the last of her powers to allow herself to grow bigger when she is about to be defeated. Though the Kyoryugers form Gigant Kyoryujin and the Seitengers form HyakuTenSeireiOh, Adana’s powers seem to be vast—powerful enough to hold both robots off on her own. The teams decide to combine their Braves and Hasureiki with the power of the ultimate melody. Having obtained the power of the Dino Hope and the Light of Hope and combining it with the melody’s power, they focus their powers into one powerful blast to finally destroy Adana. The scattering rain of light coming from the explosion heals the teams’ injuries as the Priestess’ lullaby have been heard faintly in the background once more, before fading completely.
After the battle, the Seitengers give their goodbyes to their parents’ spirits and the Kyoryugers did the same to Torin. Soon after, Helen pulls Ian away from the others and upon reaching the nearest cave’s mouth; Ian saw a smiling Mifune Shiro standing there that surprises him. The partners’ reunion was only for a few minutes, though. But it is more than enough for Ian. The others learn that Helen has met Shiro and Ian in one of her travels and that Shiro have actually helped her with her research for one of her novels. Shiro was Ian and Helen’s common friend. The reason why Helen has traveled and left the Mizuhashi mansion once more was because Shiro appears in her dreams two weeks before—just at the same time Torin appears in Itsuki’s dreams. Helen has been tasked to retrieve a soul summoning stone somewhere in Europe in order for her to fulfill Shiro’s wish of communicating with Ian even just for a while for the last time.
Later that night, the Seitengers and the Kyoryugers join forces to prepare the best birthday party for the Vessels’ mentors and finally have fun interacting with each other. This time, they did so without a care about enemies threatening to kill off people important to them. Souji also has the best time because he finally meets his secret favorite novelist Hanasaki Kikue—which turns out to be Helen’s pseudonym, has his collection of Hanami-sensei’s novels got autographed, and also receives a complimentary copy of her next novel already signed (the book that is supposed to be released two weeks from that time) along with a video letter in reply to his fan letters, just as Misae has promised to him. He doesn’t care even if Ian and Amy teases him about it because Shuichi, Natsume, and surprisingly, even Ucchii backs him up.