The Boss Battle Enemy they're about to face now is a creature introducing itself as Jinmenju, being a creepy tree made out of splintering wood with human heads instead of flowers or fruits, using its roots to walk, the upcoming battle taking place on a suitable platform with those big gears all around it. As the fight against this disturbing opponent begins, Themis imagines the Boss Battle Song to be Skillet's "Splinter":

(Skillet's "Splinter": https://www.youtube.com/watch?v=clRrDJ233yY)
"Here I lie again inside this broken body,
wrestle against the tree, my muscles aching,
to get up now is death, to die is to really live,
my flesh is restless, twisting, spasms in my back increasing.
Splinter me (splinter me), splinter me (splinter me),
my heart, my head,
splinter me."

Everyone of the good guys gets right to attacking, with Gaia doing the usual Helping Hand move to support her daughter. Mackenzie makes the guess that they may just need to aim for the creature's many creepy head fruit things, so that's what they do, but without it seeming to do much. Though it's to be noted that the force of the attacks against it pushed it a little on the battle platform. Jinmenju then manages to grab Six with its splintering wooden branches to hurt via those splinters though Six weirdly enjoys that despite getting damage from it. Themis attacks the branch with her sword to get the enemy to let go of her deviant ally. Yannick obliviously asks: "Did your idea work, Mackenzie?" "Nope, sadly not.", the Mesprit acknowledges with Alastair then noting: "We did push it... a little bit." "The gears...", Gaia catches on, "We gotta push it off this platform! Make sure to attack him from the right directions to get him closer to falling off it!" "Ooohh.", the demonic dog named Six approves, "I love seeing living things getting brutally crushed!"
But first, the scary Jinmenju shoots leaves with sharp edges at its opponents, with the good guys and Six managing to dodge that, after which they do as planned, attacking the tree-like enemy with their attacks to push him a bit further. Gaia doesn't even use Memento during this fight, since she could conclude that she is of more aidance if she joins the offensive approach to make the goal of pushing it off the platform at least a bit quicker. The Dachsbun does still have Dazzling Gleam and Psychic Fangs after all. For its next turn, the enemy with an unease causing appeareance uses some kind of spell or whatever else that is which makes every opponent who currently stands on the ground get attached to it like via roots, with separation from that being both painful and HP damaging, so the group at least learns that the next time this attack comes, they could avoid it with a well-timed jump during this attack... though the Lake Guardians don't tend to be on the ground to begin with and Six can fly.

It's after this point that Six finds out how Puruel must have made a rule that protected anyone opposing them from being possessed just in case if a demon capable of that would tag along with Themis's group. And also unfortunately for the non-Pokémon ally, using fire-based attacks doesn't just burn up the whole tree, but it does at least make pushing it with attack force easier. Jinmenju is continuing by rolling logs covered with thorns towards its opponents to jump or fly over, followed by the team of seven slowly progressing further as their attacks keep pushing this thing closer to the edge, though it's still a bit of a way left to go. The Boss Battle Enemy is then striking with some of its roots by using them kind of like whips and then it's the mostly good guys attacking once more.
The fight keeps going like this for several more turns and while Themis's team can't manage to dodge and avoid every single enemy attack, they do get Jinmenju closer and closer to the edge of the battle platform. And eventually, the force of their attacks does push it off that platform, causing it to fall right between the surrounding gears which crush the enemy, much to Six's excitement.

Someone actually opens the room Arceus and Mew are locked inside of. It's a familiar face to the two Mythical Pokémon, as Arceus notes: "Cresselia?" "Yeah, let's not waste any time with being surprised now.", the Lunar Pokémon states, "We gotta go before Puruel catches onto anything. Follow me." Cresselia then quickly leads Arceus and Mew through the building they're in right now, which turns out to effectively be Puruel's own palace, something Arceus had no idea of, making Cresselia point out: "How oblivious are you to things around you??", with Arceus affirming: "Yeah, I... I never looked as much as I should have... but I genuinely intend to do better now."
However, their way through Puruel's palace is ultimately blocked when Darkrai gets in their way. Arceus points out right away: "Darkrai! You shall not oppose me! Especially since that would be one against three for you.", though Darkrai replies in a smug way: "Actually... it's two against two.", at which point Cresselia stops hiding what's really the case: "Awww did the creator of the universe really fall for this trap? Hehehe... unfortunately for you, my boyfriend here has other plans for you than Puruel appears to have." "Boyfriend??", Arceus did not expect that to be the relationship between those two moon-related Pokémon, with Darkrai clarifying: "Yeah yeah yeah, Cresselia and I are working together to... kill you ourselves. Something I believe Puruel should have done!" This makes Mew wonder then: "Why'd you get us out of the locked room then?" "Too little space for a fight.", Darkrai remarks.
However... the mini-fight breaking out from this then leaves Arceus and Mew as the winners rather quickly, it's like THE God and his holy son against two lower deities after all. Yep, looks like the involvement of Darkrai and Cresselia ended up actually leading to Arceus and Mew to get to escape. As a response to that and while Arceus and Mew manage to get away, the defeated Darkrai notes: "Ugh... maybe you and I should uhh... head back to Earth... before Puruel finds out how we just messed up. Even if I didn't even go through with the whole nightmare thing Puruel wanted me to do, I doubt he'll be happy to see me now after all." "Just for the record.", Cresselia adds, "Getting Arceus and Mew out of there to fight them was your idea."

After this successful escape, Arceus decides: "I need a coffee break right now. This whole situation is stressing me out." Mew sarcastically remarks: "Yeah, that's an appropriate time to have a coffee break." The Mythical father and son duo then decide to rest in the Distortion World for now, where Giratina (in his Distortion Forme) is, so that they can more safely do so considering the current situation, while also trying to figure out how exactly they'll go about solving the problem, as most angels don't seem to be showing enough courage to fight alongside Arceus while the remaining few are conspiring against him just like Puruel and Khamuel. While walking over one of the platforms where what looks like some kind of trees appear and disappear constantly, Arceus ends up walking against a tree that appears right in front of him, causing Mew to giggle some.
Giratina isn't very talkative, though things are clearly kind of awkward between him and Arceus, though Arceus does tell the Ghost and Dragon Type Pokémon: "Giratina... Look, I'm sorry. I'm actually sorry. I want to apologize now, for my own antagonizing behavior towards... towards you, a very long time ago. I admit that I was not exactly the most caring or kind creator I could have been." Giratina still remains quiet but at least gives his creator a semi-understanding look and nod in response. "I'll do better from now on.", Arceus adds, "That's a promise. I've been... ignorant and cold for long enough now."

Next Chapter: https://www.furaffinity.net/view/55402889/

Previous Chapter: https://www.furaffinity.net/view/55317460/

First Chapter: https://www.furaffinity.net/view/53818365/