Asta and Yuno vs Meliodas and Ban
Asta is in Demon form, and has only the Demon-Dweller. No Demon-Slayer.
Yuno has complete control over Bell.
Asta is bloodlusted (like in his fight with Vetto).
Meliodas can use Assault Mode.
Ban has no immortality.
Neither is bloodlusted.
No prep, no prior knowledge.
Bonus round: Yami joins team BC, and High Noon Escanor joins team SDS.