Once upon a time Mona and Zhongli went on vacation. For the first time in her life she didn't spend all her Mora on more astrology books. Also Zhongli called in a favor from Childe. What kind of favor?
I dunno something about keeping his new recruits above the ground. 
Anyway the only question on their minds was where to go on vacation. The question had them stumped so Mona decided to leave it in the hands of fate.
Mona: What is Final Fantasy?
Yes so in this scenario she scried but there's that mirage machine and something something she tuned into my Constellation or something. And it just so happened that I was thinking about
They packed their bags and headed off using the cool new Domain Mona got that has the power to teleport them to other universes today for some reason.
Zhongli: Ah we've been sent to your friend's mirage.
Me: No in this scenario that's not Fischl's castle it's Pandaemonium from Final Fantasy 2.
Zhongli: ...
Me: But this one's not from Final Fantasy 2 it's more like Dissidia because that way we can bring in more characters.
Zhongli: ...
Me: It'll work out. Just trust me.
Me: -ahem- Anyway-
The happy couple explored the final dungeon of Final Fantasy 2 taking on a few random encounters and picking up some Genji level equipment off them.
Zhongli: Isn't this the same-
Me: Yeah it's the same Gen as in Genshin! Isn't that cool?
Monax: ...
Me: But sometimes it can be written with 3 dots on the left side like this 源 or be a totally different word like the era name of Japan 元. Yay kanji amirite?
Monax decided to ignore the disembodied voice of the player talking to them from beyond the 4th wall and moved on. They eventually found a being with a tail similar to Gorou only instead of a dog tail it was a monkey tail.
???: Today's not a good day for a date.
As he said this another person manifested, a blonde woman in an elegant white dress.
Mona: Is that an Archon?
Zhongli: No I sense she is something different than I though perhaps comparable in stature.
???: Zidane don't be afraid.
Zidane: But I'm powerless. There's nothing I can do for them.
Me: Ok that's nice and all but we need to keep the ball rolling so I can get in some more cameos.
All: ?
Me: Mona and Zhongli this is Zidane and the non-Archon god over there is Cosmos. Everybody familiar now? I'm pretty sure there's some way to get to Kingdom Hearts from here.
All: ...
And so following the disembodied voice they eventually came upon a TV.
Me: Well I mean that'll work.
Zhongli & Cosmos: What is this "tv" you've led us to?
Me: It'll get us to Earth the Persona 4 version. From there I think we can get to Super Smash and that'll work for my purposes too.
All: ...?
Me: Well ultimately I'm hoping to break out into the Sea of Quanta and that way I have a loophole on the contest because the Imaginary Tree is technically all possible universes.
Otto: Ah a man after my own heart.
Me: No. I don't simp Kallen. All my Crystals and Dorm Supply go toward HoT and HoS. But hey if you're here I guess I already messed up reality enough to punch a hole in the tree?
All: ...
Me: Hmmmm at this point I wonder if I'm supposed to be called Traveler, Captain or Player. I suppose I'll go with Captain Traveling Player!
All: ...
Paimon: Even Paimon can come up with a better name than that.
Me: Where's that recipe for Emergency Food. I know I have it somewhere.
Paimon: Paimon takes it back!
With the pathways open all the characters of Final Fantasy, Persona, Genshin and Honkai eventually congregated and foun-
Mona: Hang on so you hijacked our vacation just so you coul-
-found their way to the breach in the Imaginary Tree where they could have a huge beach party at the ummmm let's go with here!
And together they feasted on Mei's awesome Teriyaki BBQ Kebabs and Himeko's Sangria Punch. Final Lesson? What Final Lesson? What are you talking about? Anyway that takes care of setting and characters. Now let's talk abilities.
Mona: Who are you talking to?
Fu Hua: I'd suggest they're talking to the "audience."
Mona: Audience?
Me: Who's up for beach volleyball?
And so they played 4-sided beach volleyball.
Mona: Wait what's 4-sided volleyball?
Me: That's 4-sided beach volleyball sweetie. Please keep up.
And so they played 4-sided beach volleyball. On the Genshin team was the happy couple Monax alongside their allies Xinyan, Kazuha, Ganyu and Yae.
Yae: My my what have you gotten yourself into this time Morax?
Zhongli: At this juncture I dare not chance a guess.
On the Persona side (let's just say it was the TV world of Persona Q2) we have Joker and Yu alongside Yukari, Futaba, Yosuke and everybody's favorite idol Kujikawa Rise!
Yosuke: Hang on a second. Beach volleyball is played with 2 on a team!
Me: Shhhh nobody needs to know that.
Dainsleif: That voice. It sounds familiar.
Me: No it doesn't! 
Representing Honkai it's of course our trio of Valkyries Kiana, Mei and Bronya (let's just go swap her out with the Post-Honkai Odyssey version)
Mei: Wait what?
along with Durandal, their class monitor Fu Hua and teacher Murata Himeko!
Zhongli: Murata. That reminds me-
Me: No it doesn't!
And finally our Final Fantasy dream team led by Captain Tidus!
Tidus: I'm the ace!
Me: Sure crybaby.
He is accompanied by Tifa, Rikku, Lightning "Eclair" Farron-
Light: What was that?
-Balthier, Cid and an obligatory brooding protagonist Squall Leonhart!
Rikku: Wait which Cid?
Me: Yes.
-ahem- Let the games begin!
Mimo: You know this is about Time Travel too right?
Me: Notice the still alive Himeko-chan.
Kiana: Still alive?
Me & Mimo: 
Right let the games begin!
Now a normal game of 4-sided beach volleyball would be boring right?
Mona: Normal game of 4-sided beach-
Yes it would be boring so instead this game allows the use of all relative abilities! You've got all the Personas under the sun thanks to the powers of Joker and Narukami Yu. Rise's even converted her Himiko into her combat form from Persona 4 Arena Ultimax. Naturally since we're playing on their beach the Honkai team have their weapons drawn. They don't have their battlesuits packed though so that could put them at a disadvantage. As for the Genshin team well there are 2 Archons present and somebody who can predict the future. But the Final Fantasy team is actually led by the only character that is a professional athlete.
Tidus: And don't you forget it!
That said we are playing volleyball and I'm pretty sure all you need is somebody that can spike a ball-
I guess that's game- but wait!
Kiana with the last minute save!
And she's out of the game.
Mona: Normal game of 4-sided beach-
Yup it looks like the Final Fantasy team has the ball now.
Boom Tidus knocks it over to the Persona side with his signature Sphere Shot!
And it's denied by Izanagi! The ball-
Mona: Are you done yet?
Me: But I didn't get to the part where Cid uses his airshi-
Mona: Are you done yet?
Me: Yes ma'am.
And so everybody went home and Monax was free to head back to the site of Mona's Domain on Minacious Isle where they found a nice little dilapidated tower overlooking the night sky to spend some quality time.
The End
Tips and Tricks from a Super Casual Genshin f2p
