Finally watching the entirety of Gurren Lagann is helping me streamline a weird MLP idea I had several years back. One that crosses over the settings, not in characters, but a general concept and escalation of the plot.
There's a meme in the fandom about Rarity fighting a giant crab. I'm not entirely sure where it originated from...it may have been a random background moment, or something? Anyways, if I went with the TTGL thing, she'd then fight a house-sized crab, a mountain-sized crab, a planet-sized crab, a solar-sized crab, the Cancer constellation, then the Crab nebula.
Heck, with giant crab enemies, there's even a sort-of parallel I can do to the opposing forces of Spiral and Anti-Spiral: Carcinisation, the tendency of crustaceans to evolve into crabs. Then (supposedly) mustelification, the tendency of land animals to evolve into weasel-like shapes, is also a thing. Supposedly, because I can't really find any concrete evidence, just some 'wow isn't this cool' social media posts, but it would still work as a parallel.
(Rarity would probably scream herself silly at the thought of becoming more like a weasel though lol)