After a few hours of journeying underwater in the FW-02 Jetmarine, Ken's party reached Myu's home; Erisen, a Seafolk settlement on an island. A huge commotion struck the town when an unknown black object emerged from underwater but it was later thrown aside when the daughter of the woman most seamen tried to impress was revealed.
Ken and co introduced themselves as adventurers who took the mission to bring the missing girl home and without delay they were led to her mother's house because Myu refused to be separated from Ken. After a due reunion, Remia, Myu's mother offered hospitality to Ken's party in her home.
Later Remia becomes perplexed by Ken's unexpected reactions to her teases after she learnt what Myu referred to him as. Most teens or young men Ken's age would be flattered or blushing when a woman of her beauty approaches them but Ken rather answers her teases with serious advances which causes the girls to look at Remia as if they were on a battlefield rather than a caring mother they did before.
With her perceptive nature, Remia saw Ken has someone who goes in immediately an opportunity is given after evaluating himself, so if she wasn't careful she might be caught in his claws which gives her a certain unidentified feeling.
When it came to time they were ready to leave, Ken left Myu a iPad that will enable them to to talk and see each other from great distances. Remia just gave a normal bye fearing what Ken might say or do if she continued her antics now.
...
Knowing the conditions to see the Sunken Ruins of Melusine, the underwater Labyrinth, Ken used the proof of clearance of the Volcano Labyrinth to lead his party underwater. Since the Labyrinth's trail concept was "Exposing the horrors that the gods have inflicted upon the world" through vivid illusions, the group were able to clear it with relative ease since they were either not believers or not from this world.
Gifted with Restoration Ancient Magic, a proof and a mini-submarine after clearing, the strongest party met the slimy, jelly-like monster which they met after entering the labyrinth and couldn't kill since it seemed the whole entrance was it's body. It then showed it's fullness after the party were teleported outside the labyrinth.
The monster was called a Devourer, a giant gelatinous sea-based monster, which got its name from basically being able to dessolve anything that it swallows. Ken very much recognized it from the anime but since said anime skipped how the OG story protagonists defeated it and the manga wasn't there yet when he died, Ken had to get creative by combining [Deconstruction] and [Decomposition] to cast Disintegration magic which did the job regardless of the monster's [Ultra-Regeneration] abilities.
This of course reaffirmed the party's inner feelings of being thankful that Ken was by their side and that if he got possessed, not even Yue with her genius magic abilities and [Self-regeneration] could survive something like this. And the way it was cast, the party could conclude that it had the same operation as Mist Dispersion magic used in the Volcano Labyrinth.
After that Ken and party spent some time relaxing and spending time with Myu and his women away from all the traveling. He didn't do much more than accepting Remia's teasing of calling him Anata or Darling to distinguish himself from the Seafolk men trying to woo her.
Hagime and Koari also took this time to be romantic by enjoying the beauties of nature the Town had to offer.
After reassuring Myu of his eventual return and their safety, Ken and company flew to their next destination in the "mother" of Jetmarine, FS-1 Black Widow, with it's aesthetics resembling the Zephyr One– one of SHIELD's aircrafts, and since Ken was one person the craft was only large but incomplete according to the plans Ken had for it.
It only had a bathroom, a dinner room and a bedroom, the rest were just empty spaces waiting for a purpose.
...
A lot changed by the time the world's strongest party got to Heiligh Kingdom.
Daisuke Hiyama was reported dead by those who were saved by Ken, apparently Meld Loggins was more ruthless than Ken remembered but the Hero party didn't know who killed him and chucked it to another knight who did it in self defense.
The Hero party didn't suspect Eri because she was with them when Daisuke was found dead, and through Eric's blabbering when she had trapped them, they got to know Daisuke was an accomplice who killed the kingdom's knights.
After he killed Daisuke during his ambush, Meld went into hiding deep within the castle to lick his wounds leaving Eri Nakamura alone to follow through with her plan of aiding the Demons in their invasion as well as making Kouki Amanogawa hers after killing some nuisances, i.e. her classmates.
Even after failing to kill Ken's party in the Volcano Labyrinth, Freid Bagwa still had the guts to follow through with the Heiligh Kingdom invasion plan because he received word; "the 'gods' will be sending an envoy to kill the 'heretics' and will not interfere with 'mortal' conflicts".
With such reassuring words and an insider, Freid had confidence in falling the Holy Kingdom and see the end of his adversaries.
Ken on the other hand left the Apostle Noint to Hagime, while Yue, Shia and Riveria dealt with Freid and his army of Demons and beasts. And as promised by Ken, Tio was left to destroy the Church along with the Pope and everyone related.
Before the battle all of Ken's women had to play; rock, paper, scissors-- inorder to choose who would face and kill Freid for his 'cowardly' attack on Ken. Yue won in the end, and the rest of the Demon army suffered from being the targets of Shia and Riveria's frustrations.
Whichever assistant Hagime and the girls needed, the Third eye provided with it's combustion attack, so Ken was left to rescue Aiko– who was gaining attention by trying to gather her students to safety after learning of the truth thus was kidnapped and imprisoned in the Church; and Shizuku as well as the heroes.
After Noint was defeated and Freid Bagwa was killed by the Riveria's Slaughter Spear bursting his heart after Yue failed to stop his escape after killing Uranus, Ken captured Eri Nakamura as the second inmate in his prison.
The party along with Aiko were rewarded with Spirit Magic after fulfilling the conditions of clearing at least two Great Labyrinths and killing a devout of the gods or at least playing a part in it.
After gaining this Ancient Magic and it's information, Koari petitions for her soul to be transferred into Noint's strong Apostle body inorder to be more useful to the team. The party obliges as Yue made an Ice coffin to keep Koari original body and Koari puts it in her own Storage ring, which by the way everyone had one; except for Hagime who got to keep the Treasure trove to house his numerous creations.
Shizuku and the rest of the heroes who learnt of the truth and a viable way home from Aiko after the incident with Eri Nakamura and the Demon invasion decided to set their sights on other Labyrinths beginning with the Labyrinth underneath the now destroyed Church on the 'Mountain of God'.
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