As someone watches Ninjago/watched it as a kid, I can’t help but notice how alike Lloyd and Shadow are
Descendants of all-powerful beings (Lloyd being the First Spinjitsu Master’s grandson, Shadow being Doom’s son)
Both SHOULD be considered royalty, but they aren’t (First Spinjitsu Master creating Ninjago, Doom being the leader of the Black Arms species
Both are hybrids (Lloyd being a mix of Dragon/Oni/Human, Shadow being an Alien/Hedgehog hybrid)
Both are the son of a “Dark Lord” (LORD Garmadon, Doom being referred to as such in one of Shadow 05’s endings)
Both had access to new powers before they were lost (Lloyd becoming the Golden Master and having them drained, Shadow with his Doom Powers)
Both were responsible for their father’s defeat (Lloyd being prophesied to defeat Garmadon, Shadow defeating Doom twice)
Both have been betrayed by someone they trusted (Lloyd with Pythor and Harumi, Shadow trusting his father in 05)
Both have been manipulated by those they have trusted (Lloyd with Pythor and Harumi (again), Shadow being manipulated by Doom and Gerald)
Both were put through a lot of trauma (canon), and there’s always room for more (fanworks, mine included)
Both were involved with possession of some sort of(Lloyd BEING possessed by Morrow, Shadow nearly being possessed by Doom in Shadow Generations)
In conclusion: It'd be cool to read a fic about the main Sonic cast meeting the ninja, with Lloyd and Shadow just relating to each other via their similarities and traumatic experiences. Tails and Jay are bonding about inventing, Knuckles and Cole are testing each other’s strength, Zane, PIXAL, and Silver are watching this all play out, Amy is bonding with Nya, Kai and Blaze are sparring with their fire (nearly burning something down), and Sonic is watching all this play out with Wu and being like “Yeah, this is normal.”