help on an idea

[Guilmon and a shotgun]

Yumi's made some good suggestions, but i will add my own take on how to include the Chosen Children (I'm assuming this means Digidestined).

So you have Lucemon and Abraxas who've joined forces in the aim to create a utopia, they're our Protangonists i'm assuming. So, to accomplish this goal they need to get rid of Digimon not suited for a utopia which includes Digimon with human partners.
The Chosen Children (Our Antagonists), whilst wandering through the Digital World (Backstory for why this is can be added depending on what season the Digidestined are from or if they are OCs too then one can simply be invented), are confronted with a scene where Digimon that are pure enough for Utopia are donning black uniform armor plating and destroying the Digimon that are impure in a small village.
The Chosen children fight them off and are now in the story, ready to fight alongside the impure Digimon against this purity-obsessed invasion.

Hope that helps, you don't have to use my version but even if you do it's not nessesary to use it word for word. Take bits you want and hopefully it'll help you complete your Saga.