>>93492213>I've become enthralled with the idea of Marco meeting Toffee and Moon officially.
Are you going for a new idea or adapting an episode?
I guess how to go about it would depend on your intentions for Toffee and Moon's characterization in this story, and how you want their relationship with Marco to be.
You could have something like "Diaz Family Vacation" where Star and Marco sneak off to Mewni for whatever reason, explore the Forest of Certain Death, wander into one of those old monster temples and get caught by Toffee, who could disapprove (Marco letting Star sneak back to Mewni and putting herself in danger, when he's supposed to be her guide and guardian on Earth) or approve (seeing Star and Marco support each other and maybe fight something off).
If you were thinking more of a formal meeting, like "Toffee and Moon have caught on that Star and Marco are smooch buddies and want to size him up" then that's a lot more focused of a concept, but you'd have to more careful considering how to portray everyone since it would be almost wholly dialogue and character-driven drama (not that it would necessarily be "dramatic").>I have this weird idea for a drama piece that MonStar is actually the product of Moon's spell in this timeline
Some kind of "interspecies conception" spell isn't that strange of a concept, especially after Eclipsa was introduced. That's always how I assumed Monstar could be a thing, and even before all this "monster-loving" stuff it was the easy solution to the question of if Humans and Mewmans were biologically compatible.
Though it kind of sounds like you're going for the angle of treating her like she's a magical chimera or homunculus (monunculus? Mewmunculus?) whose literally dependent on some magic component or stimulus inside her to function, which is a pretty wild and interesting take.
TL;DR: it sounds like you really want to expand your work and go full-blown AU, which is cool, but I'd advise you to seriously plan ahead.