(War of the Worlds x Loud House)

Ten years after the Martians invade the world, Humanity in 2015 advanced thanks to the leftover tech the enemy left behind and reverse engineered.  Lincoln and his sisters are learning about their enemy, in the newly reconstructed schools, when they encounter something familiar.  Its up to them to stop the second wave before the tensions escalate into another war, a war where there would be no surviving the aftermath.

(Loud House A.E. A Titan A.E. Crossover)

Join the Loud Family as they flee with Humanity's last hope, And a big secret they learn along way as they journey to a new world with the Drej chasing them.

(Loud House x Gunstar Heroes Crossover)

Based on the Lore of the Gunstars, and the sequel, this time the Louds are swept up in the war of the Treasure Gems, and deals with the aftermath of the first game, but new enemies arise in the wake of the war, and its up to them and the weapons they have to stop the new threats and a blast from the past will reveal more than a simple threat to the world at large.

(Loud House x Gradius Crossover)

Takes place in the wake of Gradius 4 and a year before 5, the Louds were to participate in the Gradius Planetary Tour, as full fledged Gradius Pilots (aged up of course) But a familiar foe rears up and makes a mess of things, and separates the sisters and Lincoln!  Can Lincoln, Maggie and Clyde save them from the ills of the Bacterions, or will their first mission be their last? (Maggicoln pairing)

That's all for now, I'll edit if someone else had the idea...